Bass ( ; , deep, low) describes tones of low frequency or range from 16-256 Hz (C0 to middle C4). In musical compositions, these are the lowest parts of the harmony. In choral music without instrumental accompaniment, the bass is supplied by adult male bass singers. In an orchestra, the bass lines are played by the double bass and cellos, bassoon and/or contrabassoon, low brass such as the tuba and bass trombone and the timpani (kettledrums). In many styles of traditional music such as Bluegrass, folk, and in styles such as Rockabilly and jazz, the bass role is filled by the upright bass. In most rock and pop bands and in jazz fusion groups, the bass role is filled by the electric bass. In some 20th and 21st century pop genres, such as 1980s pop and Electronic Dance Music, the bass role may be filled with a bass synthesizer.