Writing in 5/4 is perfectly reasonable. You could also make the time signature either (3+2)/4, which would mean "five beats per measure, with a 3+2 pulse pattern", or you could write both time signatures next to each other, which would mean "alternate measures of 3/4 and 2/4."
T:5/4 Time Signature Options
z | [M:3+2/4] z3/4 z2/4 || [M:32/44] z3/4 | z2/4 ||
(NOTE: the 4 should be centered at the bottom of the (2+3)/4 time signature.)
Loosely speaking, the fundamental differences would be these:
- 5/4 would mean one strong beat per measure (beat 1), and one semistrong beat per measure (beat 4).
- (3+2)/4 would be equivalent to 5/4
- [3/4][2/4] would mean two measures both with strong beats (beat 1, respectively).
These are interpretive rules of thumb, but phrasing or other musical considerations could make them more equivalent or less.
It also should be noted that the metric divisions within 5/4 time (3+2 or 2+3) can be clarified, if necessary, by the use of a dotted bar line. This is particularly helpful in a situation where the divisions change.