What is "ionisation"

n. (alternative spelling of ionization English)

1. n. the condition of being dissociated into ions (as by heat or radiation or chemical reaction or electrical discharge); "the ionization of a gas" [syn: ionization]

2. the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas [syn: ionization]

Ionisation (1929–1931) is a musical composition by Edgard Varèse written for thirteen percussionists. It was among the first concert hall compositions for percussion ensemble alone, although Alexander Tcherepnin had composed an entire movement for percussion alone in his Symphony No. 1 from 1927. The premiere was at Carnegie Chapter Hall, an annex to New York City's Carnegie Hall, on March 6, 1933, conducted by Nicolas Slonimsky, to whom the piece was later dedicated. One critic described the performance as "a sock in the jaw."