hondrou thoughts: January 2015

Thursday, 15 January 2015

Moolodeon - Arduino Midi Melodeon

And next up... I've also been following this one for a while and is another of my favourite projects out there. Lee O'Donnell aka Bassmaker has this great hack of a cheap Chinese import Melodeon that he's dropped an Arduino into along with buttons and a pressure sensor to make a fun little instrument.

Lee also has some excellent pictures showing off the design and the electronics. It's just a little bit of a shame that the source code isn't also posted. Here's some pictures of the construction:

I'm not going to comment more than this as Lee has done such a good job on his site, but here are the YouTube links of it in action.

Lee also has a cracking project explaining his SD Card Midi sample player that generates the fantastic sounds from this instrument. I'll probably blog on that separately later, but check it out!

Ocarduina - Arduino Ocarina

Another New Year's resolution - there's quite a few interesting musical instrument projects and technology hacks that I have been following a looking at for a while. One of the things that I wanted to do with this blog was to start to highlight the ones that I've seen that are really cool. Last week I updated on the interesting Hurdy-Gurdy projects I'd seen, this week it's time to point out one of the first projects I saw and was an early inspiration for the Arduino.

This is still one of my favourite projects. The Ocarduina. I came across this on the Mountain Ocarina forum, I think after my wife saying that these little instruments were getting some ground vs. learning on the recorder and I'd had a look at one of the original iOS cool apps from Smule.

This is just such a fantastic project enhanced even more by Nephiel talking about it on the forum as he goes through the development and putting videos up on YouTube.

Here's the first prototype demo:

And then a few more as the project evolves - see how the micro-switches have been changed to thumb-tacks and are using capacitive sense instead which allows some additional effects such as note slide-off.

Playing some scales:

Playing Cumberland Crew

And Tam Lin

And finally the finished concept packaged up into a tiny little box... what a great electronic musical instrument!

Friday, 9 January 2015

Musical Symbols in WPF/Silverlight

I had some interest over this week looking at being able to show some musical symbols in a Silverlight / WPF application and had expected this to be a relatively simple thing but ended up chasing down quite a lot of little dark alleys until I found a couple of good answers. So, with my New Year's resolution of posting a lot more of these little thoughts, I'll see how far I can get describing the journey.

For starters I thought this would be simple. Everything is now unicode, right, they have Japanese, Korean, Maths notation and other symbols, there must be a code-page for musical notation. Yes! and well, no! If you go to the Unicode specification, there's a whole set of musical symbols defined. http://www.unicode.org/charts/PDF/U1D100.pdf Next bit of searching was to find a suitable font that had these symbols included. I finally found 'Symbola.ttf' which included it, but probably not my final font. Enough to try though. I dutifully installed this and then wanted to have a look at what symbols were there. The big problem is that these are in UTF-32. Take a look at charmap (on Windows), this only extends up to UTF-16. So I couldn't see them. Undeterred and still expecting this not to be a problem I had a long fight with Silverlight to try to get it to show this unicode encoding, finally giving up when I realised it only extended to UTF-16 (basically this means you can only go as far as \UFFFF or  as otherwise written. This is a problem, as the musical notation is all above that, with the treble-clef at U+1d120. Hmmpf.

So, where could I go then? I did have a poke around in some other fonts, and hoped that they would have musical notation in the private areas. More of which later, but at this point I didn't find quite what I was looking for and so, I'll continue my journey as it uncovered some other interesting things on the way to what I got to solve my problem.

Next step, I took a look at EasyABC, as I had posted previously I've been using this on my Mac and am really liking it, so I took a look at the package and the python scripts. First thing to note that the actual musical rendering is made by abc2ps, an excellent little project written in C. The musical format in this case was not quite what I was looking for (need to come back and detail a bit more when I get a chance).

After that, as I've been playing with it as well, I took a look at VexFlow. Now, this was interesting, digging down in the source on github, they have the file gonville.js that appears to have some interesting path-like font descriptions. In trying to understand this I uncovered quite a long and interesting thread on pluggable fonts for VexFlow that I must go back and read in more detail.

The thread lead me on to SMuFL - Standard Music Font Layout (http://www.smufl.org/) - now I was getting somewhere! I had an interesting read around this and found the Bravura.otf OpenText format font. This revealed a number of interesting things - firstly it is available under the SIL Open Font license and secondly it implements all of the specified unicode musical symbol range U+1d100 - U+1d1dd, however these are mapped into the unicode Basic Multilingual Plane in the standard private area at U+e000 so fall within the scope of UTF-16 and hopefully usable by Silverlight! Now we're sucking diesel!

Next step I returned to the previous bashing of my head against a Silverlight wall and with a bit more googling, finally got the font in and showing a treble-clef. There's a quite a few false trails out there and the Silverlight route throws up some slightly different challenges to a standard WPF app, but the best advice was from Apres Pro Silverlight 5 in C# here on Font Embedding It's important to follow the note on using the # to show the name of the font, not just the file containing the font.

My code directly in WPF finally looked like this...

In this case I have the Bravura.otf font file in a sub-directory called Fonts and the properties have Build Action set to Resource and Copy to Output set to Copy if newer. The name of my application is 'AgScore'. Nice!

Now, there's an interesting little note in the Apres book that says if you can't get this working for you in your app, then turn the fonts into graphics and use the Path notation. Nice! To backtrack a little. I had tried this unsuccessfully earlier when I took one of the lines of the gonville.js file path-like notation and had converted that into the path mini-language. It sort of worked, but I didn't have the energy to follow that through when I thought there should be a simpler answer and fond the SMuFL links. The little note in the book points to a link hich details how to get the text into a path string from code. I didn't want to fight this from Silverlight itself and the approach shown in the link uses a backend service by the looks of it, so I decided to bash at this directly in a C# application and get the path information to see how it worked. Here's how it looks:

    // Set up the Culture
    string strCulture = "en-us";

    System.Globalization.CultureInfo ci = new System.Globalization.CultureInfo(strCulture);

    // Set up the flow direction
    System.Windows.FlowDirection fd = FlowDirection.LeftToRight;

    // Set up the font family from the parameter
    FontFamily ff = new FontFamily("D:\\Users\\gbcollia\\Documents\\Visual Studio 2010\\Projects\\AgScore\\AgScore\\Fonts\\Bravura.otf#Bravura");

    // Create the new typeface
    System.Windows.Media.Typeface tf = new System.Windows.Media.Typeface(ff,  
                                                                        FontStyles.Normal, 
                                                                        FontWeights.Normal 
                                                                        FontStretches.Normal);

    // Create a formatted text object from the text,

    // culture, flowdirection, typeface, size and black

    FormattedText t = new FormattedText("\uf472", ci, fd, tf, 20, System.Windows.Media.Brushes.Black);

    // Build a Geometry out of this
    Geometry g = t.BuildGeometry(new Point(0, 0));

    // Get the Path info from the geometry
    PathGeometry p = g.GetFlattenedPathGeometry();

    // Get the path data info
    string pathdata = p.ToString();

I then unashamedly pasted this path data into a path in SIlverlight to see how that looked as follows:

Very nice. I had a treble-clef, although not quite how I wanted it. So, after a quick, lazy google, I scaled using this suggestion (http://stackoverflow.com/questions/5109058/wpf-the-right-way-to-scale-a-path). Omitting the path data for clarity:

<Path Stroke="Black" Fill="Black" StrokeThickness="0.1" Data="..."

Height="80" Width="30" Margin="0" RenderTransformOrigin="0, 0">

<Path.RenderTransform>

</Path.RenderTransform>

</Path>

This pretty much gets me what I wanted. Now, I just need to do a simple routine to export all of the fonts I need into paths, put them into a separate XML file (or similar) and I can use them in Silverlight programmatically to render some nice graphics.

Hope this is of use to someone else struggling with the same questions.

Monday, 5 January 2015

eBay 3.4.0 upgrade for iPad

Wow! I just got stung! Unfortunately I upgraded the app the other night as it only noted some additional improvements but not detailing that this had been completely redesigned. What a disaster. It seems like they've tried to duplicate Pintrest. Ok, I love Pintrest for some things, but I liked previous eBay interface as it was. This is terrible. I'm now relearning navigation and most of my home screen is taken up with a useless image. Not what I wanted.

Now, the worst part is that Apple do not provide any way to be able to roll this back unless you keep a backup. Huh??? I have to keep the backup when they have a server that contain all the old versions of the app. Why can't I just delete and re-download from them?

Why, why, why eBay. It's been nearly a month now and you still have not rolled back despite so many 1 star reviews. What happened to releasing new functionality as new versions and not just upgrades. It seems now I will have to either a) suffer b) not use eBay (the most likely choice) or c) go back to using the web-page, which pretty much means like b). At least I have not upgraded all my devices yet.

VexTab for Guitar TAB Editing

Following on from looking at ABC Notation and EasyABC, as my usual dabbling is with a guitar, I wanted something just as simple this which would allow me to jot down melodies along with chord progressions and lyrics but also in TAB. Given what we have with web technology, it's sad that so much is still put into ASCII and then painfully rendered on forums detailing various riffs and licks. There should be a better way. Surprisingly there is not that much out there.

After a bit of searching I came across VexFlow and VexTab notation originally by 0xfe touting itself as HTML5 music engraving. Poking around a bit and messing around in the playground, it seemed to be just the thing. Great! No need to re-invent the wheel! I particularly liked that VexTab seems to allow entry in score or Tab and if entered in Tab optionally the score could be shown as well. I did find the score entry a little klunky compared to EasyABC, but the Tab entry seemed pretty fine, although getting the score to match exactly what I wanted was a bit harder than I hoped for getting the beaming right.

After trying the online playground, I downloaded the source bundle and played myself from the web-page locally (I wanted to stretch the display over more than 3 bars each line - I finally found an easier way to do this using options in the first line).

Using Silent Night again (not a very rock selection, I know!), it looks something like this in VexTab

And renders like this in the online playground:

Cool! Not quite so neat and succinct as ABC Notation, but it sort of does the job. My real gripe is that I just could not seem to figure out how to get text/lyrics to align no matter how much I followed the tutorials or tried to work this different ways. I'll need to give it more of a look.

Now, ideally if there was some sort of harmony between EasyABC and VexTab we'd really be somewhere.

Abc Notation and EasyABC for Music Editing

A number of times last year I had the need to be able to quickly jot down some musical melody and the accompanying chords and lyrics and most times either resorted to some quick home code or bashing it into the relevant tool - Word, Excel or scoring software depending on the immediate need. In early Dec I was looking for some traditional English tunes and bumped into ABC Notation. How could I have missed this! Apparently I'm not the only one as one of my more musical colleagues had never heard of it either.

There's a whole bunch of traditional tunes at Traditional Music UK with guitar and mandolin tabs if that's your thing.

There are a number of really good tutorials on ABC Notation most of which are referenced from the main website, which also has a search reference for tunes marked out in the notation. The latest standard is ABC Notation V2.1. I'm going to call out the excellent two page reference from Stephen Merrony as particularly worthwhile getting hold of, along with the tutorial on LeSession as it was the one I read as I dipped my toe in. Such an excellent resource, it's been a gold-mine to look at over Christmas.

I've been using Nils Liberg's EasyABC on the Mac and it's fantastic. Really pleased how this just does the job I'm looking for. Easy to use, has pretty much all the functions I need, free and allows export in a number of different formats. What's more, it is open source, and although Python is not my tool of choice I like having the opportunity to contribute or be able to add in my own export if needed.

The strength of ABC is that it does seem to be succinct, concise and just gets the job done without too many flourishes to worry about, but the back-up when those niggly little notation bits are needed. Admittedly my needs are modest, so it might run into barriers trying to use it for orchestral scores, but that's not my bag (at the moment!). The only thing I frustratingly couldn't work out how to do was to show a muted note. If anyone knows how to do this, please drop me a note!

This is how Silent Night looks in ABC Notation:

X: 0
T: Silent Night, Holy Night
Z: Franz Gruber
Z: Copyright © 2004 Douglas D. Anderson
Z: Released To The Public Domain
L: 1/4
M: 6/8
Q: 1/4=60
V: P1 name="Staff"
%%MIDI program 1 19
K: C
[V: P1]  (G3/4 A/4) G/ E3/ | (G3/4 A/4) G/ E3/ | d (d3/4 B/) B3/ | c (c3/4 G/4) G3/ | A A/ (c3/4 B/4) A/ | G3/4 A/4 G/ E3/ | A A/ c3/4 B/4 A/ | G3/4 A/4 G/ E3/ | d d/ f3/4 d/4 B/ | (c3/ e3/) | (c/ G/) E/ G3/4 F/4 D/ | (C3/ C3/)|]
w: Si-_ lent night! Ho-_ ly night! All is_ calm, all is_ bright. Round yon Vir-_ gin Mo- ther and Child. Ho- ly In- fant, so ten- der and mild. Sleep in heav- en ly peace,_ Sleep_ in heav- en ly peace._

And the corresponding score:

Royal Institution Christmas Lectures

An essential part of the Christmas/New Year break. This years' Royal Institution Christmas Lectures 'Sparks will Fly: How to hack your home' excelled again at bringing technical concepts into the home to a younger audience in an understandable and enjoyable way. Prof. Danielle George was inspiring and a real engineering role model.

This year was particularly enjoyable as the first time I was able to watch it with my own children. I remember how inspiring these were to me when I first saw them.

The final of the three was just brilliant as it brought together hacking electronics, software and music into a learning journey that lead to a final climatic orchestral playing of the Dr Who theme tune. Great and inspiring stuff!