The Dark Side of the Moon Tour began on January 20th 1972 at the UK's Brighton Dome, and concluded almost two years later at London's Rainbow Theatre, on November 4th '73. Covering the UK, US, Europe and Japan, there were two separate legs promoting the album, one in 1972 before the record's release and another in 1973 afterwards, together covering 128 shows. Pink Floyd had worked out a basic structure of Dark Side of the Moon in late 1971, and played it at almost every gig the following year, alongside a set of earlier live favourites. By 1973, the album was finished and the live performance resembled the completed work. To re-create it in concert, the group added saxophonist Dick Parry and female backing singers to the show. The stage performance was enhanced with extra visual effects and an improved quadrophonic sound system. Floyd first took the tour to the USA on April 4th 1972, and stayed there for a month. They went back for another jaunt in September '72, when they also performed 2 shows in Canada. By March 1973, the band were back in the States, and on 15th of the month, played at Philadelphia's Spectrum, where they put on one of the entire tour's best concerts. The Dark Side set from this show - plus a couple of encores from the Floyd back catalogue - were recorded for live broadcast by WNEW FM Philadelphia and transmitted across the local area. This new CD title now features this entire broadcast for the first time, allowing fans to hear this remarkable gig, in many cases, for the first time.