The key characteristic of classical music that distinguishes it from popular music and folk music is that the repertoire tends to be written down in musical notation, creating a musical part or score. This score typically determines details of <answer>rhythm</answer>, pitch, and, where two or more musicians (whether singers or instrumentalists) are involved, how the various parts are coordinated. The written quality of the music has enabled a high level of complexity within them: J.S. Bach's fugues, for instance, achieve a remarkable marriage of boldly distinctive melodic lines weaving in counterpoint yet creating a coherent harmonic logic that would be impossible in the heat of live improvisation. The use of written notation also preserves a record of the works and enables Classical musicians to perform music from many centuries ago. Musical notation enables 2000s-era performers to sing a choral work from the 1300s Renaissance era or a 1700s Baroque concerto with many of the features of the music (the melodies, lyrics, forms, and <answer>rhythm</answer>s) being reproduced.
The score determines how various parts are coordinated, pitch, and what other detail?
rhythm