Jazz piano is a word for the ways pianists play jazz. The piano has been an important part of the jazz, in both solo and group settings. Its role is one of the biggest. This is because of the instrument's combined melodic and harmonic nature. For this reason it is also an important tool in the understanding of jazz theory and arranging for jazz musicians and composers. Together with the guitar, vibraphone, and other keyboard instruments, the piano is one of the few instruments in a jazz combo which can play chords, instead of only single notes (as with the saxophone or trumpet).