* He enjoys listening to the radio: Ponyboy often mentions turning on the radio, especially in his room. This suggests he likes popular music of the time, which would likely include rock and roll, pop, and country.
* He enjoys listening to music with Darrel (Darry): While the specific music isn't mentioned, it's likely they listen to music that is popular with older teenagers, which would again include rock and roll and country.
* He mentions the song "Stay Gold" by the band "The Eagles": This suggests a fondness for classic rock, a genre that was very popular in the 1960s and 70s.
While we can't know for sure what Ponyboy's favorite music is, it's safe to say that he enjoys popular music of the time, which would include rock and roll, pop, and country.