Be bop, also known as bebop, is a jazz style that originated in the 1940s. It is characterized by complex melodies, rapid tempos, and improvisation. Finding antonyms for this word can be a bit challenging, but there are some possible options. One antonym could be "slow" or "relaxed," as be bop is typically fast-paced and energetic. Another could be "predictable" or "conventional," as be bop is known for its unpredictable and unconventional style. Additionally, "unstructured" could be an antonym, as be bop often involves improvisation and deviates from traditional musical structures.