re the 6/8 3/4 question. You are confusing beat values here, I think. 6/8 has a beat value of 2 dotted quarters per measure. The joining of tails of eighth notes into 3 in 6/8 (or any compound time signature) is to denote this beat value- they are not triplets. How fast they play is set by the speed setting- moderato, adagio, or dotted crotchet = 100 etc. When learning to play 6/8 you count 1 & 2 & 3 & 4 & 5 & 6 & (just remember this is a count , not the actual beats).
5/8 is not compound time, but simple time- 5 eighth note beats per measure.
To tell whether a time signature is compound, the top number must be divisible by three, but larger than 3 eg. 6/8, 12/8, 9/4 etc. To find how many beats divide the top number by three. To find which note equals one beat, divide the bottom by 2, then dot the resulting note. eg. 9/4 is 3 beats each of a dotted half not.
Any questions on how quick they are is relative to a metronome setting.
Edited by cobb2 - October 31 2009 at 18:04