By Matt Roper Time is being called on bars, basements and back rooms which are part of rock and pop history. There are uncertain futures for venues where some of today’s biggest names played their first gigs. They include the pub where a shy then-18 Kate Bush faced drunken football fans and the spot where a young Reginald Dwight, aka Sir Elton John, belted out Ray Charles hits. Last year, 125 boozers stopped doing live music – half of them closing altogether, citing soaring costs. Yet there is still a huge appetite for live music with an estimated 5.6 million people watching a band in a smalle…