I'm a huge fan of PLANET OF THE APES and its various sequels. My favorite of the four follow up movies is the second one, BENEATH THE PLANET OF THE APES. One of the reason I like so much is its fine score by Leonard Rosenman. While not in the same league as Jerry Goldsmith's amazing music for the first movie Roseman's work is very good and quite effective. I have both scores on CD and I have to admit that it is BENEATH that I return to more often.
Here's a link to an interview with the composer in which he comments on his Ape score.