TOCCATA, tō̇-kä′tȧ (It., touched). In music, a term originally applied to compositions written for keyed instruments, thus having a somewhat more restricted meaning than sonata, a composition for any instrument. The oldest toccatas preserved are some written for the organ by Claudio Merulo (published 1598). They generally begin with full chords which gradually give way to passage-work among which small fugato sections are interspersed. The modern toccato does not materially differ from that of Merulo. Compare Sonata.