event
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## event

event — Generates a score event from an instrument.

## Description

Generates a score event from an instrument.

## Syntax

    event "scorechar", kinsnum, kdelay, kdur, [, kp4] [, kp5] [, ...]

    event "scorechar", "insname", kdelay, kdur, [, kp4] [, kp5] [, ...]

## Initialization

“scorechar” -- A string (in double-quotes) representing the first p-field in a score statement. This is usually “e”, “f”, or “i”.

“insname” -- A string (in double-quotes) representing a named instrument.

## Performance

kinsnum -- The instrument to use for the event. This corresponds to the first p-field, p1, in a score statement.

kdelay -- When (in seconds) the event will occur from the current performance time. This corresponds to the second p-field, p2, in a score statement.

kdur -- How long (in seconds) the event will happen. This corresponds to the third p-field, p3, in a score statement.

kp4, kp5, ... (optional) -- Parameters representing additional p-field in a score statement. It starts with the fourth p-field, p4.

| Note
Note that the event opcode cannot accept string p-fields. If you need to pass strings when instantiating an instrument, use the scoreline or scoreline_i opcode.

## Examples

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

Example 271. Example of the event opcode.

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

    <CsoundSynthesizer>
    <CsOptions>
    ; Select audio/midi flags here according to platform
    ; Audio out   Audio in    No messages
    -odac           -iadc     -d     ;;;RT audio I/O
    ; For Non-realtime ouput leave only the line below:
    ; -o event.wav -W ;;; for file output any platform
    </CsOptions>
    <CsInstruments>

    ; Initialize the global variables.
    sr = 44100
    kr = 4410
    ksmps = 10
    nchnls = 1

    ; Instrument #1 - an oscillator with a high note.
    instr 1
      ; Create a trigger and set its initial value to 1.
      ktrigger init 1

      ; If the trigger is equal to 0, continue playing.
      ; If not, schedule another event.
      if (ktrigger == 0) goto contin
        ; kscoreop="i", an i-statement.
        ; kinsnum=2, play Instrument #2.
        ; kwhen=1, start at 1 second.
        ; kdur=0.5, play for a half-second.
        event "i", 2, 1, 0.5

        ; Make sure the event isn't triggered again.
        ktrigger = 0

    contin:
      a1 oscils 10000, 440, 1
      out a1
    endin

    ; Instrument #2 - an oscillator with a low note.
    instr 2
      a1 oscils 10000, 220, 1
      out a1
    endin

    </CsInstruments>
    <CsScore>

    ; Make sure the score plays for two seconds.
    f 0 2

    ; Play Instrument #1 for a half-second.
    i 1 0 0.5
    e

    </CsScore>
    </CsoundSynthesizer>

Here is an example of the event opcode using a named instrument. It uses the file event_named.csd.

Example 272. Example of the event opcode using a named instrument.

    <CsoundSynthesizer>
    <CsOptions>
    ; Select audio/midi flags here according to platform
    ; Audio out   Audio in    No messages
    -odac           -iadc     -d     ;;;RT audio I/O
    ; For Non-realtime ouput leave only the line below:
    ; -o event_named.wav -W ;;; for file output any platform
    </CsOptions>
    <CsInstruments>

    ; Initialize the global variables.
    sr = 44100
    kr = 4410
    ksmps = 10
    nchnls = 1

    ; Instrument #1 - an oscillator with a high note.
    instr 1
      ; Create a trigger and set its initial value to 1.
      ktrigger init 1

      ; If the trigger is equal to 0, continue playing.
      ; If not, schedule another event.
      if (ktrigger == 0) goto contin
        ; kscoreop="i", an i-statement.
        ; kinsnum="low_note", instrument named "low_note".
        ; kwhen=1, start at 1 second.
        ; kdur=0.5, play for a half-second.
        event "i", "low_note", 1, 0.5

        ; Make sure the event isn't triggered again.
        ktrigger = 0

    contin:
      a1 oscils 10000, 440, 1
      out a1
    endin

    ; Instrument "low_note" - an oscillator with a low note.
    instr low_note
      a1 oscils 10000, 220, 1
      out a1
    endin

    </CsInstruments>
    <CsScore>

    ; Make sure the score plays for two seconds.
    f 0 2

    ; Play Instrument #1 for a half-second.
    i 1 0 0.5
    e

    </CsScore>
    </CsoundSynthesizer>

## See also

event_i, schedule, schedwhen, schedkwhen, schedkwhennamed, scoreline, scoreline_i

## Credits

Examples written by Kevin Conder.

New in version 4.17

Thanks goes to Matt Ingalls for helping to fix the example.

Thanks goes to Matt Ingalls for helping clarify the kwhen/kdelay parameter.

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