Apple Soundtrack - Manual (Page 18)

18 Chapter 1 Audio and Music Basics
Digital Distortion
To record sound with the widest possible dynamic range, the input level must be set
high enough to capture the complete audio signal. When the input level of the signal is
set too high, however, the signal exceeds the maximum level that can be sampled or
reproduced accurately, resulting in digital distortion. Digital distortion is defined for
most digital audio applications, including Soundtrack, as any time the signal rises
above 0 dB. Even a single sample above 0 dB can produce noticeable distortion, which
you hear as a sharp crackling sound in the audio output. Digital distortion is nearly
always undesirable, and Soundtrack includes audio meters and other controls so that
you can identify and remove distortion from your projects.
Basic Music Concepts
You can create professional-sounding music projects in Soundtrack without any
background or training in music. In order to understand how the different elements in
a piece of music work together, and how you can use them to plan and create projects
in Soundtrack, it’s helpful to know some basic concepts about music.
Rhythm and Tempo
Rhythm is the most essential of all elements of music. People respond to rhythm
unconsciously by tapping their feet or moving their bodies in time to the rhythm.
When the rhythm in a piece of music changes, most people feel a difference in the
character or mood of the music right away.
Rhythm defines the sense of time in music by creating a recurring pulse. The feeling of
rhythmic pulse in music can be subtle (for example, in classical music and some
electronic music), or it can dominate all other elements of the music (as in tribal
drumming or in dance music).
There are usually several layers of rhythm occurring simultaneously in a piece of music.
The strongest rhythmic layer occurs in regular units called measures. Falling within each
measure are a number of softer pulses called beats. The beat that coincides with the
beginning of the measure is called the downbeat. There can also be more subtle pulses
between beats. In the Soundtrack interface, the Beat ruler and Beat display show the
division of musical time into measures, beats, and beat divisions.
Time