It's a way of cutting down costs; most keyboards don't require you to hold arbitrary combinations of letters, arrows and the likes, so they fit the different keys onto registers that can only handle so many at much.
If you're interested in hitting quads, go into stepmania's input test and mess around with holding down random sets of keys. Each keyboard may or may not have a combination that works well. Here are some sets you can try:
qweiop
123/iop (on the number line) 789 (on the numpad)
4586 or 4826 (on the numpad)
LDUR for your left hand/finger, 4568/4268 on the numpad for your right hand/finger
If you cannot find a set of inputs that works, fear not; triples and quads are not judged until the the last note is hit, so you can 'slide' into such a chord and still hit it all with a marvelous if you time things right. |