Can there be one answer to this question?
The "live" sound of a paint-peeing rock band (which as Bobo notes, often sucks -- in a good way), and the "live" sound of an un-amplified singer/songwriter are very different things (and so on for many different genres), so getting them right might ask for pretty different systems.
IMHO, many of the comments above seem to have rock, or large scale music, in mind.
John
The "live" sound of a paint-peeing rock band (which as Bobo notes, often sucks -- in a good way), and the "live" sound of an un-amplified singer/songwriter are very different things (and so on for many different genres), so getting them right might ask for pretty different systems.
IMHO, many of the comments above seem to have rock, or large scale music, in mind.
John