How did composers edit sounds to create tape music?

Composers created tape music by recording sounds onto magnetic tape and then using various manipulation techniques to transform them into a unified composition. This process allowed for precise control over every aspect of the original sound material.1

Common editing and manipulation methods included:

• Tape Splicing: Cutting and rearranging tape to combine different sounds, create new juxtapositions, or alter the attack and decay of a sound.1
• Speed and Direction Changes: Altering the speed of the tape to change pitch and tempo, or playing the tape backward to reverse a sound's evolution.12
• Signal Processing: Using filters to alter timbre, adding reverberation or echo-chamber effects, and adjusting sound intensity.12
• Mixing and Looping: Superimposing multiple sounds (mixing) or creating repeating patterns using tape loops.1

These techniques were central to musique concrète, where composers used natural sounds as raw material, as well as in studios that focused on electronically generated tones. By treating the tape recorder as a musical instrument, composers could move beyond traditional performance to create complex, artistic sound montages.123