Recording audio directly into Ableton Live’s DAW is simple, requiring only an audio track and the specification of the input channel. This recording method has advantages over an editor, such as Audacity, in that it allows the selection of arbitrary input channels and easily facilitates the layered synchronization of new material onto old.
1) Create an audio track in Live
2) In the new track’s input/output section, select the audio input channel you wish to record from.
3) Arm the record for this new track (WARNING: if the input is a microphone, make sure the speakers are turned down, monitoring only through headphones).
4) Arm the master record (circle, top-level “transport” control) and hit “play” (triangle)