Sorry, spotted an interesting post.. Not sure if the thread is active though. Local network version could be an interesting idea, sure the internet with it's latency issues causes problems, but being <20ft away from each other on a gigabit network almost eliminates that... The thought would be to have a system which allows multiplayer within the same room/building (Imagine the LAN parties).. Song start/note timing could be pretty accurate as it'd be as easy as syncing clocks between 2 or more computers, or to have a master/slave system going on whereby only one machine would have to play the music and the slave machines sync up, allowing players to participate by feeding results/note hit markers forward to the master (and echoing the real tone cable through the slave machine's speakers as normal)... But the thought of a group of players with various guitar types belting at the same song sounds fun ;) Just an idea, doubt it'll get anywhere though.. (Btw my first post, please shoot me..)
