<- C I ->

I STATEMENT (INSTRUMENT or NOTE STATEMENT)

     i  p1  p2  p3  p4  ...   
This statement calls for an instrument to be made active at a specific time and for a certain duration. The parameter field values are passed to that instrument prior to its initialization, and remain valid throughout its Performance.

PFIELDS

     p1   Instrument number (from 1 to 200), usually a non-negative integer.
          An optional fractional part can provide an additional tag for specifying 
          ties between particular notes of consecutive clusters.  A negative p1
          (including tag) can be used to turn off a particular `held' note. 
     p2   Starting time in arbitrary units called beats.   
     p3   Duration time in beats (usually positive).
          A negative value will initiate a  held note (see also ihold).  
          A zero value will invoke an initialization pass
          without performance (see also instr).   
     p4   |
     p5   |   Parameters whose significance is determined by the instrument.  
     .    |
     .    |

SPECIAL CONSIDERATIONS

Beats are evaluated as seconds, unless there is a t statement in this score section or a -t flag in the command line.

Starting or action times are relative to the beginning of a section ( see s statement), which is assigned time 0.

Note statements within a section may be placed in any order. Before being sent to an orchestra, unordered score statements must first be processed by Sorter, which will reorder them by ascending p2 value. Notes with the same p2 value will be ordered by ascending p1; if the same p1, then by ascending p3.

Notes may be stacked, i.e., a single instrument can perform any number of notes simultaneously. (The necessary copies of the instrument's data space will be allocated dynamically by the orchestra loader.) Each note will normally turn off when its p3 duration has expired, or on receipt of a MIDI noteoff signal. An instrument can modify its own duration either by changing its p3 value during note initialization, or by prolonging itself through the action of a linenr unit.

An instrument may be turned on and left to perform indefinitely either by giving it a negative p3 or by including an ihold in its I-time code. If a held note is active, an i statement with matching p1 will not cause a new allocation but will take over the data space of the held note. The new pfields (including p3) will now be in effect, and an I-time pass will be executed in which the units can either be newly initialized or allowed to continue as required for a tied note (see tigoto). A held note may be succeeded either by another held note or by a note of finite duration. A held note will continue to perform across section endings (see s statement). It is halted only by turnoff or by an i statement with negative matching p1 or by an e statement.

<- C I ->
Prepared from the MIT Media Lab Csound Manual, PJN, Nov 1994.