All the open source music simulators i'm aware of, either focus on one instrument and how to present information to that instrument, such as Piano Odyssey or Synthesia, which fulfill their role for piano.
Are game interface focused like Digiband, and do not support real interfaces: Keyboards, ( Guitar/bass as in 4-6 strings and 24 frets), or real music (aside from drums).
Superseq is targeting Linux, Windows, and OSX. Primary dev work is done under linux, so it is likely to be the best supported. Blender, and specifically the Blender Game Engine (BGE) is being used. Low level functions like midi input are written in c/c++ and interface via open sound control (osc) to send data to the game in realtime.
Perhaps i'm a little selfish being a guitar player with a midi interface on my guitar (roland gk series) but Its all just music, so if i want to see scrolling sheet music, or piano keys, or guitar tablature, it shouldn't matter. I'm aware of midi violin's and am pretty sure there are other midi interfaced intruments out there. SuperSEQ will be designed in a way that once an instrument interface is added, it will turn up as a display mode. That is what SuperSEQ is focusing on, a transparent interface to as much content as can be.
Standard midi files are all over the net. This is where portsmf comes into play. A large part of learning music is practice, so when someone may want to try something new, they can spend a minute online, find some new midi files to import, pick the channels to assign to each player ( keyboard display mode for ch1, guitar display mode for ch2, drum display mode for ch9) and play away. Granted, all files will not work for input for all intrument types, but for example, any single note melody will translate 1 to 1 for guitar, and drum tracks should be able to be extracted from channel 9 in most midi files, one of my focus at first will be the guitar logic display side of it. The other views: Keyboard, drums, and standard sheet music are pretty straight forward scrolling with time.
For anyone thats spent hours playing Space Invaders, Pacman, and Duck Hunt, It isn't difficult to see how something very simple, can also be very entertaining. Alongside showing music to play, to have music that can be played with. Think of the star spangled banner generating an obsticle course to fly a plane through, and the only way to get through is correctly playing the song, or have a nightmare of zombies attacking to flight of the bumblebee . . . at full speed. Sitting down to a game to many audiences is often less intimidating then sitting down to a "Lesson", and defeating a level, can be more motivating then practicing the same thing over and over.
Alternatively, take the approach of getting home from a long days work and wanting to relax. I personally like to play music to relax, but often may not want to work through something new to play (Being especially bad at sight reading standard music) but would like to have more variety. Learning should be challenging, entertaining, and accessable.
Once the information is in, no matter what controller is being used, any game can be played, or training done.
One of the advantages to using blender, is its system for packaging and releasing games based on the bge, a single archive can be distributed for any platform, uncompressed, and ran (this does not include low level input functions, which will require a seperate package (real time midi or audio data)
I'm currently working on the backend functions, and getting data into blender via osc. Initial tests are done, and i'm learning python now.
Related to blender, we're actively looking for people who are interested in becoming involved with SuperSEQ for content creation and minigame ideas.
All game logic is written in python, and runs in the blender game engine.