Objective

Using PureData for reading, playing, recording, and scratching audio files

Digital audio recordings are made up of a series of sample values; the audio sample rate for the recording establishes how many sample values are recording in teach second of town. For example, 44.1KHz, 44,100 samples are recorded every second.

Puredata uses tables (like those uses to store pitches and amplitudes for a melody) to store audio samples. The tabread4~ and tabwrite~ objects allow reading and writing of values into tables at audio rates.

Consider the follwoing important concepts, implications and questionsof this example:

1. You can use tables and arrays in Puredata to work with audio samples
2. The speed at which you play an audio file affects its perceived pitch

Steps and observations

1. Open the 1.c.iii.7_music-synth-sampling.pd patch in Pd-extended.
2. Follow the institutions in the patch.

Comments

For a challenge,

• record and audio sample and play it back at 1/2 the origianl speed
• create a patch that scratches a sound back and forth with an oscillator