Bandwidth, Slew Rate and All That Jazz
To reproduce an audio signal faithfully over the whole audio band, your circuit needs to have a bandwidth at least as large as the audio band. But that’s not the only requirement: your circuit needs to maintain that bandwidth from the lowest to the highest signal level. That’s where the crux lies: it is relatively easy to get a nice wide bandwidth for small signals, only to have it breakdown with high signal levels due to the dreaded slew rate limiting.