well, in theory, a 16 bit recording can have a dynamic range of 96dB, and a 24 bit recording can have a dynamic range of 144dB. in practice, this is limited by equipment specs (preamps, A/D's, etc, etc...) to somewhere around 110 to 120 dB for a 24 bit device.
that said, I'd be surprised if any concert had a noise floor lower than -40 or -50 dB. So, from a practical standpoint, any concert is only going to have a dynamic range of 40 to 50 dB.
When considering 24 bit recording, I'd say the resolution of the recording is just as important, if not more-so, than the dynamic range. with 24 bit recording, there is more information at each sample, so each sample is a more accurate representation of the analog wave entering the A/D converter. because of this, 24 bit recordings can seem much more natural and lifelike. It's hard for me to describe in words the difference in sound between 16 and 24 bit recordings, but the difference is definitely there.