Creating a Loop using a Vinyl Record - earliest method for looping
Schaeffer discovered that he could lock-groove records. Instead of spiralling toward the center of the record, the needle could be made to stay in one groove creating a loop.

Creating a Loop using Reel to Reel Tapes
Creating a loop consisted of taking tape with recorded material and splicing the ends of the tape to make a loop. E = Erase head; R = Record head; P = Playback head

Short Loop

Long Loop

Pitch
Slowing the tape makes the pitch go lower. Speeding up the tape makes the pitch go higher.

Reversing the tape
Reversing the reels of recorded material and playing the tape backwards can be used to create reverse reverberations and attacks.

Echo
Straight line delay: The signal is recorded, monitored by the playback head, and sent back to the reverse reverberations and attacks.

Flange (A type of Delay)
Early flanging effects were created by lightly touching the tape reel as the track was being 'bounced' to another track.

You are going to achieve similar effects on the computer.