Much more than most jazz clubs, Ronnie Scott's matters. It is a London landmark, and so much a part of the history of jazz in Britain that it ought to have a blue plaque on the Frith Street exterior wall. But changes are afoot, as I discovered on a recent trip to London. The club was closed - for the first time since 1959 - and will reopen on June 26. The London jazz community awaits with a mixture of high hopes and a degree of trepidation. This, after all, is an institution. Ronnie Scott and his partner Pete King originally opened Ronnie Scott's Jazz Club in Gerrard Street, Soho, as a basement dive. Their ambition was to create a venue like one of the great New York clubs where British talent could be heard. It was successful well beyond their early expectations, and Scott and King wanted to go one step further by presenting American talent as well. They were blocked, however, by the musicians unions on both sides of the Atlantic, which between them ensured the necessary work permits could not be issued. From the beginning, Scott, with his unshakable commitment to jazz and British love of bad jokes he relished telling nightly between sets, was the club's public face. King had a better grasp of the business side, and was a natural diplomat. It was, accordingly, King who negotiated an end to this egregious example of musical protectionism. In 1961 the Tubby Hayes Quartet were given the necessary permits for a gig at the Half Note in New York, and Zoot Sims became the first of a long list of great American jazz musicians to take up residency at Ronnie's. The deadlock had been broken, and transatlantic musical exchange became possible at many other venues as well. In 1965 Ronnie Scott's moved to the larger premises it occupies to this day in Frith Street, keeping the original club going in tandem until its lease ran out in 1967. Over the past 40 years a who's who of jazz musicians from all over the world has played there, in an environment absolutely geared to enjoyment of jazz. Conversation while a set is in progress has traditionally been frowned upon, and tolerance of mobile phones has always been very low indeed. The room is packed with memories of past performances and past performers, many of them sadly no longer with us. My first visit to Ronnie's, more than a quarter century ago as a student, was to see the late Joe Pass in person for the first time. It was also the first time I heard Scott's deadpan nightclub comedian routine, of which Spike Milligan was a big admirer. On other occasions I heard him play, and there wasn't much doubt as to which was his real metier. Sadly, he was silenced as a musician in the mid-1990s by unsuccessful operations on his teeth. A fine and passionate player who had suffered for some years from bouts of depression, with his true vocation taken from him, even Ronnie Scott couldn't see the funny side any more. He started washing sleeping pills down with cognac, and in December 1996 died suddenly of the lethal effects of the combination. Jazz clubs are precarious businesses at the best of times, and Ronnie's has been no exception. It has nearly had to close a number of times over the years, but the founding partners somehow kept it on the rails. After Scott's death King soldiered on until the club's 45th anniversary, but, understandably, without his associate of almost 40 years his heart was no longer absolutely in it. In 2005 he found a buyer among his regulars and the business is now owned by theatrical impresario Sally Greene. Greene is known for bringing slightly down at heel theatres back up to scratch, and when the club reopens it will be apparent whether she's managed a refurbishment, which the place certainly needed, that preserves its unique atmosphere. There will also be some continuity at the top. King has accepted the position of the club's honorary lifetime president, and his son Chris takes over as general manager. Residencies for international acts appearing at the club will now be shorter, making it possible to book big names with hectic touring itineraries who would otherwise be playing one or two nights in London at concert venues. Given the new admission prices I fear Ronnie's is no longer going to be a place to casually drop in for a late drink and to catch the last set of the night - the latest in a series of blows this month for long-time member John Prescott, who, like Kenneth Clarke on the other side of the House of Commons, was in the habit of doing just that after late-night sittings. It's reassuring it's still going to be there though.