<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>t Statement (Tempo Statement)</title>
<link rel="stylesheet" type="text/css" href="csound.css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.76.1" />
<link rel="home" href="index.html" title="The Canonical Csound Reference Manual" />
<link rel="up" href="ScoregensTop.html" title="Score Statements and GEN Routines" />
<link rel="prev" href="s.html" title="s Statement" />
<link rel="next" href="v.html" title="v Statement" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">t Statement (Tempo Statement)</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="s.html">Prev</a> </td>
<th width="60%" align="center">Score Statements and GEN Routines</th>
<td width="20%" align="right"> <a accesskey="n" href="v.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry" title="t Statement (Tempo Statement)">
<a id="t"></a>
<div class="titlepage"></div>
<a id="IndexTStatement" class="indexterm"></a>
<a id="IndexTempoStatement" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">t Statement (Tempo Statement)</span>
</h2>
<p>t —
Sets the tempo.
</p>
</div>
<div class="refsect1" title="Description">
<a id="idp76789080"></a>
<h2>Description</h2>
<p>
This statement sets the tempo and specifies the accelerations and decelerations for the current section. This is done by converting beats into seconds.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="idp76789840"></a>
<h2>Syntax</h2>
<pre class="synopsis"><span class="command"><strong>t</strong></span> p1 p2 p3 p4 ... (unlimited)</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="idp76790880"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>p1</em></span> -- Must be zero.
</p>
<p>
<span class="emphasis"><em>p2</em></span> -- Initial tempo on beats per minute.
</p>
<p>
<span class="emphasis"><em>p3, p5, p7,...</em></span> -- Times in beats (in non-decreasing order).
</p>
<p>
<span class="emphasis"><em>p4, p6, p8,...</em></span> -- Tempi for the referenced beat times.
</p>
</div>
<div class="refsect1" title="Performance">
<a id="idp76793064"></a>
<h2>Performance</h2>
<p>
Time and Tempo-for-that-time are given as ordered couples that define points on a "tempo vs. time" graph. (The time-axis here is in beats so is not necessarily linear.) The beat-rate of a Section can be thought of as a movement from point to point on that graph: motion between two points of equal height signifies constant tempo, while motion between two points of unequal height will cause an accelarando or ritardando accordingly. The graph can contain discontinuities: two points given equal times but different tempi will cause an immediate tempo change.
</p>
<p>
Motion between different tempos over non-zero time is inverse linear. That is, an accelerando between two tempos M1 and M2 proceeds by linear interpolation of the single-beat durations from 60/M1 to 60/M2.
</p>
<p>
The first tempo given must be for beat 0.
</p>
<p>
A tempo, once assigned, will remain in effect from that time-point unless influenced by a succeeding tempo, i.e. the last specified tempo will be held to the end of the section.
</p>
<p>
A <span class="emphasis"><em>t statement</em></span> applies only to the score section in which it appears. Only one <span class="emphasis"><em>t statement</em></span> is meaningful in a section; it can be placed anywhere within that section. If a score section contains no <span class="emphasis"><em>t statement</em></span>, then beats are interpreted as seconds (i.e. with an implicit <span class="emphasis"><em>t 0 60</em></span> statement).
</p>
<p>
N.B. If the CSound command includes a <a class="link" href="CommandFlags.html#FlagsMinusLowerT"><em class="citetitle">-t flag</em></a>, the interpreted tempo of all score <span class="emphasis"><em>t statements</em></span> will be overridden by the command-line tempo.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="idp76879320"></a>
<h2>Examples</h2>
<p>
Here is an example of the t statement. It uses the file <a class="ulink" href="examples/t.csd" target="_top"><em class="citetitle">t.csd</em></a>.
</p>
<div class="example">
<a id="idp76880288"></a>
<p class="title">
<strong>Example 1031. Example of the t statement.</strong>
</p>
<div class="example-contents">
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc ;;;uncomment -iadc if RT audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o t.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span> <span class="op">=</span> 1
<span class="oblock">instr</span> 1
aenv <span class="opc">expseg</span> .01, p3<span class="op">*</span>0.25, 1, p3<span class="op">*</span>0.75, 0.01
asig <span class="opc">poscil3</span> .8<span class="op">*</span>aenv, p4, 1
<span class="opc">outs</span> asig, asig
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="stamnt">f</span> 1 0 16384 10 1 <span class="comment">;sine wave</span>
<span class="stamnt">t</span> 0 240 12 30 15 240 <span class="comment">;start tempo = 240 </span>
<span class="stamnt">i</span> 1 0 2 110 <span class="comment">;tempo = 240</span>
<span class="stamnt">i</span> 1 3 2 220 <span class="comment">;slow down &</span>
<span class="stamnt">i</span> 1 6 2 440 <span class="comment">;slow down &</span>
<span class="stamnt">i</span> 1 9 2 880 <span class="comment">;slow down & </span>
<span class="stamnt">i</span> 1 12 2 110 <span class="comment">;slow down to 30 at 12 seconds</span>
<span class="stamnt">i</span> 1 15 2 220 <span class="comment">;speed up to 240 again</span>
<span class="stamnt">i</span> 1 18 2 440 <span class="comment">;stay at tempo 240</span>
<span class="stamnt">i</span> 1 21 2 880
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="s.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="ScoregensTop.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="v.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">s Statement </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> v Statement</td>
</tr>
</table>
</div>
</body>
</html>
distrib
>
Mageia
>
5
>
x86_64
>
media
>
core-release
>
by-pkgid
>
b707d9a4ee443103660a75ccb6e51334
>
files
>
2681
