In 1973, the band moved "Dark Side of the Moon" to the second set (where it would reside through 1975), and played the album version of the piece, notably the revamped versions of "On the Run" and "The Great Gig in the Sky." 1973 saw Pink Floyd go on two relatively short tours of the US, one in March to coincide with the release of "The Dark Side of the Moon" and a later one in June. Sandwiched between them were two nights at London's Earl's Court on 18 May and 19 May where they debuted the special effect of a plane crashing into the stage at the end of the song "On the Run". This was also the first year that the band took additional musicians on tour with them, unlike the earlier performances of "Atom Heart Mother" where the band would often hire local musicians.