Many musicians favor vacuum tube power amplifiers for their musical instrument use.
In this case the amplifier actually becomes part of the instrument itself. They use the distortion characteristics of the amplifier (which are easy to modify and change with tube amplifiers of this type) to provide the kind of sound they desire. Their choices can be different, but it is their choice to provide the "signature" of sound they are trying to produce.
In audio system playback, we are trying to reproduce the sound the musician and his instrument gave us, not produce something different than what the musician intended.
No playback system is entirely accurate, your choices are large, but do remember the goal is to hear what the musician and his choice of instrument, including his amplifier, did, not something other than that.
Regards,
Frank Van Alstine