|posted: 6/15/2004 at 1:16:07 PM ET|
String Instruments are in the key of C Major and play the same note which is written. As with most instruments, the viola can play in any key. This does not mean that any violist will be capable of playing in any key. Both performers must be proficient on their perspective instruments enough to know which notes are altered in each key.
From a performance/practice standpoint you should make sure that the piano is relatively close to A440 mgz and tune the viola A string to the A on the piano. If your violist is relatively experienced they should be able to tune the other strings listening for perfect fifths. If not, tune the other strings on the viola to CGDA. C being the largest string and A being the thinest one.
Hope this helps,