support uploading midi files for download

[RustoMCSpit]

studiorack/studiorack-site#36

https://github.com/ldrolez/free-midi-chords

[RustoMCSpit]

https://www.hooktheory.com/theorytab

while i wasnt envisioning uploading tablature, that would be possible as well. more of a studiorack / owlplug suggestion but having the capabilities of hookpad but foss would be incredible. total feature creep though

[RustoMCSpit]

also for metadata, allow the uploader to pick a mode. so if i write "Mode: dorian" i dont have to force it into G ionian or aeolian to upload it. also having a scale list, e.g. blues / pentatonic / etc. (like the license list) would be good.

you might be tempted to add a key metadata entry but thats wrong entirely. every melody and chord progressions can just be quickly shifted up to any key with arrow keys. the only thing the user needs to know is the mode, the key should always be a parallel key to C major (C ionian, D dorian, E phygrian, F lydian, G mixolydian, A aeolian, B locrian) as C major is a standard for these types of things. the user then can search for a specific mode and can pitch shift it themselves. we can also just have a tool to pitch shift it for them but this is basic theory. for any harmony, just make the user name the file after its roman numerals instead e.g. iii VIb i II

this has limits: what about modal interchange, non 12 tet, key shifts, etc.. these are niche and should be thought about later

[RustoMCSpit]

all midi file uploaders (as well as projects) will have to sign a CLA or something saying they have rights to upload this and if they dont they must credit the rights holders. again, it is legal to upload sheet music and midi files of songs that arent yours such as https://www.hooktheory.com/theorytab as long as you credit the owners