Jazz as a genre also counts spontaneity among its core values, just as gospel at its most inspired seeks something higher through performance. Bob Dylan, Neil Young and Bruce Springsteen hold court atop the list of rockers who strive for liberation with every performance. Some artists, of course, make an art out of veering from the script mentality. The brutal reality of mounting a major concert tour is that it requires intensive rehearsals and meticulous planning of sound, lighting and staging effects, often leaving music itself as just another element of a tightly organized script that’s repeated night in and night out with little room for deviation. One of the conundrums facing anyone who makes music for a living is that live music frequently isn’t.