midinoteoncps — Gets a MIDI note number as a cycles-per-second frequency.


midinoteoncps is designed to simplify writing instruments that can be used interchangeably for either score or MIDI input, and to make it easier to adapt instruments originally written for score input to work with MIDI input.

In general, it should be possible to write instrument definitions that work identically with both scores and MIDI, including both MIDI files and real-time MIDI input, without using any conditional statements, and that take full advantage of MIDI voice messages.

Note that correlating Csound instruments with MIDI channel numbers is done using the massign opcode for real-time performance,. For file-driven performance, instrument numbers default to MIDI channel number + 1, but the defaults are overridden by any MIDI program change messages in the file.


midinoteoncps xcps, xvelocity


xcps -- returns MIDI key translated to cycles per second during MIDI activation, remains unchanged otherwise.

xvelocity -- returns MIDI velocity during MIDI activation, remains unchanged otherwise.

If the instrument was activated by MIDI input, the opcode overwrites the values of xcps and xvelocity with the corresponding values from MIDI input. If the instrument was NOT activated by MIDI input, the values of xcps and xvelocity remain unchanged.

This enables score p-fields to receive MIDI input data during MIDI activation, and score values otherwise.

[Note] Adapting a score-activated Csound instrument.

See the MIDI interop opcodes section for details on adapting score driven instruments for MIDI or vice-versa.


Here is an example of the midinoteoncps opcode. It uses the file midinoteoncps.csd.

Example 479. Example of the midinoteoncps opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

; Select audio/midi flags here according to platform
-odac    -M1  ;;;realtime audio out and midi in 
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o midinoteoncps.wav -W ;;; for file output any platform

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1

midinoteoncps p4, p5				;puts MIDI key translated to cycles per second into p4, and MIDI velocity into p5

print p4					;display the key value when it changes and when key is pressed 
kvel = p5/127					;scale midi velocity to 0-1
kenv madsr 0.5, 0.8, 0.8, 0.5			;amplitude envelope multiplied by
asig pluck kenv*kvel, p4, p4, 2, 1		;velocity value			
     outs  asig, asig

f 0 30	;runs for 30 seconds
f 2 0 4096 10 1	

i 1 0 2 440 100	; play these notes from score as well
i 1 + 2 1440 100


Its output should include lines like:

 i1   261.62561
 i1   440.00006

See Also

midichannelaftertouch, midicontrolchange, mididefault, midinoteoff, midinoteonkey, midinoteonoct, midinoteonpch, midipitchbend, midipolyaftertouch, midiprogramchange


Author: Michael Gogins

New in version 4.20