In ska, all guitars are the same, they make fast, sharp strums up and down, with rapid mute of the strings. All the ska guitarists do the same thing, and sometimes one of the band members does a solo. One of the other ways to distinguish ska and punk is by rhythm. In punk music, the drum beat is very fast, loud and balanced. Punk guitar also uses power chords to emphasize rhythm. The ska rhythm is easier to identify because of the rhythm emitted by the guitar, which resembles a reggae rhythm. Ska and punk each have a different number of band members, and the band members have different roles. A punk band will have three or four members, one playing bass, one or two playing guitar, and one playing drums. In many bands the singer is the lead guitarist, but sometimes it's the bassist and sometimes even the drummer, but that's rare. Ska groups are much more numerous. It is normal in a ska band to have a bassist, one or two guitarists, a drummer, two or three trombones, one or two trumpets and a singer. Also, in a ska band, the singer never plays an instrument. In punk as in ska, everyone plays the guitar, trumpet or trombone and sings.