Rhythmical
Rhythmic
な adjective
Rhythm is 律動, but by adding a 的 in there we get the adjective version of that word, making it rhythmical or rhythmic.
りつどうてき
The reading is the same as 律動. The 的 part you should also be able to read by now.
この音楽はとても律動的ですね。
This music is very rhythmic.