Show HN: Convert from MIDI file to ASCII tablature (and more)

github.com

40 points by ycombiredd 6 days ago

Hi folks,

About seven months ago, via HN, I got nerdsniped into a silly guitar transcription problem and made a bunch of really senseless code but what came out of it was what I thought at the time could potentially be pretty useful - a guitar fretboard mapper and fingering scoring algorithm.

So as of yesterday morning I've finally put those bits of code to "good" use, creating gtrsnipe to convert between MIDI files (.mid) and ASCII tab (as well as VexTab and ABC notation) and any combination/direction among the set of formats.

gtrsnipe tries to intelligently find the best neck and fingering positions using a note to fretboard mapper and a scoring algorithm that is unavoidably shaped by my subjective opinions and skills as a player but it does its best to avoid objectively impossible fingerings.

See the example tabs and usage in the README and please, try your own transcriptions from MIDI and if you love or hate the arrangement it gives you, I'd love to hear about it so I can further refine the scoring algorithm.

Thanks!

omoikane 2 days ago

If I read it correctly, the mapper will score fingering based on how many frets the hand needs to stretch:

https://github.com/scottvr/gtrsnipe/blob/4cae149e1dac766c3c3...

But this doesn't seem to account for other shape concerns. The bit I am most interested in is whether this mapper can avoid barre chords where possible.

Related, I think there should also be an option to take capo into account.

  • ycombiredd 15 hours ago

    There's quite a bit more involved in the scoring, such as string hopping, runs on the same string, etc. I invite you to run --help and look at the mapper config tunables. Ideas for improvement are welcome.

ycombiredd 16 hours ago

OP here. I need to update the readme, but running it with --help will show you all of the alternate tunings and such. The mapper algorithm is nearly 100% tunable.

As I said, I'll put this info in the README, but last night I made a medium post that shows some of this (--bass, etc).

https://medium.com/@scott.vr/about-seven-months-ago-via-hack...

robbomacrae 2 days ago

Nice! This reminds me of my PhD research! I built some similar tools to go the other way (for comparing similarity with scores) but probably nowhere near as reliable as this. QQ How do you handle repeat segments? I remember having to extrapolate the x2's etc but in your you could detect patterns and do the reverse for compactness.

  • ycombiredd 15 hours ago

    Thanks! TBH I hadn't thought about handling repeating segments yet - in either direction. Because the tab-to-midi direction is mostly a novelty I haven't done much of it except with tabs generated by gtrsnipe, and since it doesn't handle repeats specially, I haven't had to parse any "x2" type notation, but now that you mention it I should. Thanks again.

jmkr 2 days ago

Awesome OP. I'll give it a shot because I've been considering doing something similar for chord charts. Glad to see abc notation support.

nartho 2 days ago

Looks interesting, too bad it's limited to 6 strings and 3 tunings, that excludes a lot of music

  • ycombiredd 16 hours ago

    I probably need to update the documentation. Since I posted I've added many alternate tunings and it supports from four to seven strings. I'm still improving it. Thanks for checking it out.

westurner 2 days ago

I looked for similar tools;

Looks like tayuya is also written in Python, on mido and music21. It has a "get all notes to play" feature, mentions LilyPond tab output as a todo, and has a get_key(midi) method built on music21: https://github.com/vipul-sharma20/tayuya#get-all-notes-to-pl...

tayuya.tabs:note_nearest_to_fret: https://github.com/vipul-sharma20/tayuya/blob/master/tayuya/...

Kord has a fretboard visualizer tool: https://github.com/synestematic/kord#fretboard-tool

Textual is another way to create CLIs for Python scripts.

What about tab playback and CLI-based scrubbing?

There was a post a week or so ago about an LWN article about spotify/pedalboard, which is written in Python and built on JUCE (C++) and supports VST3 and LV2 plugins like a MIDI player or a wavetable synth and a Guitarix effects rack: https://news.ycombinator.com/item?id=44604024#44648290