The bits per second used to encode an audio file, in kbps. Higher bitrate keeps more data and generally means better quality in lossy formats.
Bitrate is the number of bits per second used to encode an audio file, expressed in kilobits per second (kbps). In lossy formats like MP3 and AAC, a higher bitrate preserves more of the original audio data and reduces compression artifacts.
Why it matters
A track encoded at 128 kbps can sound dull or distorted through a club system; 320 kbps MP3 or a lossless file keeps transients sharp and avoids pumping artifacts that become obvious at high volume.
In practice
Sort your library by bitrate before a gig and quarantine anything below 192 kbps. Flag low-bitrate files for replacement rather than relying on them in a peak-time set.

