An instrument block is comprised of ordinary statements that set values, control the logical flow, or invoke the various signal processing subroutines that lead to audio output. Statements that define an instrument block are: instr endin An instrument block looks like this: instr 1 ;A simple sine wave oscillator aout oscils 10000, 440, 0 out aout endin Statements that define a user defined opcode (UDO) block are opcode endop See the UDO section for more information.