Since recording equipment has been an integral part of writing music it has been possible to use the original master tapes and demos to construct a song from the parts that had already been completed. Many demos are released officially if the artist has been unable (or unwilling) to complete it, or made available as a bootleg recording. The continued popularity of the Beatles led to "Free as a Bird" and "Real Love" being released in the mid-1990s after the band members pieced together incomplete recordings by the deceased John Lennon. Both songs reached the top five in the British singles chart.