MIDI IN

You may have seen this image, posted by Twitter user Threatening Music Notation .  [ Link to Youtube video in case you prefer viewing rather than reading.] The first problem is that the notes are labelled incorrectly. Or mostly incorrectly. The second is that the notes aren't spaced correctly. Or are they?   Glossing over the labelling, could the designer have intended this to be a set of notes, spaced differently from the way that we usually do? This idea intrigued me, and I set about finding a way to play the notes "as written" We have to make some decisions here. It does look very much as if the spacing is four of their notes where we would usually write three, So I'm going to take that E (labelled D) G (correctly labelled) and B (labelled C) as anchor points, and fill in the frequencies from there. I'm familiar with the table of values for the SID sound chip in the Commodore 64, this gives the values that we pass the SID to get particular frequencies.  From t...

 I've spent a little time getting MIDI output from my little theremin. I thought it would be possible using pitch bend to adjust the frequency between the midi notes (semitone steps). Good news, this is working well. Bad news, I hadn't considered the envelope of the notes. The 'steps' you hear are the attack/decay of each new note beginning. I hadn't considered this issue.  It might be possible to use a sound that has no envelope. There may still be a very slight click between notes, but shouldn't be too noticeable.  However, I don't want to require a specific type of sound. It  would be ideal if it could work with any sound patch. Is it necessary to 'note off / note on'  from one semitone to the next? Just sending note ons doesn't work because you end up with a cacophony of each note still sounding.  I've done a little reading and it's not looking promising. There is a concept of portamento in midi, but this isn't standard.  More rea...

[edit 27 Jun 24] Since this old post has been shared recently and is receiving some views (thank you for visiting) I'd like to say upfront that the project below has since developed into e-ther, the e-theremin, and then developed futher into a version 2. You can find its homepage / demo videos here:  https://peacockmedia.software/e-ther/ [original post continues....] This project began sometime last year because I wanted a theremin to play around with (the instrument you play with gestures). I very nearly sprang for an Open Theremin kit, but thought I might be able to make myself something that worked well for much less.  Cheaper kits use light-sensing components, which work optically but not optimally and are affected by ambient light. I thought that there must be sensors that can read distance accurately - and there are. These lidar sensors are allegedly millimetre-accurate and aren't significantly affected by ambient light. I'm using ones with a 50cm sensing distance. A...