The musical signal's form does never resemble a square wave. The frequency range perceived by an average adult hardly goes above 17KHz. Hence I do not give a dime to those heated discussions whether it's appropriate to test audio amplifiers using a 100KHz meander signal. But being an electronic engineer in my heart as well as by education and passion - I can assure you that giving an audio amplifier a try with 100KHz square wave test signal can reveal quite some technical qualities (or lack of those) in the design. Overshots caused by negative feedback loops or signal slopes formed by input/Miller capacitances are amongst things that are easier to observe with meander than when using sound-frequency test signal.