Here's the Ferranti Mk 1 (the successor to the Manchester Mk 1, which was in turn the successor to the SSEM) which was the first commercially available computer

Here's the Ferranti Mk 1 (the successor to the Manchester Mk 1, which was in turn the successor to the SSEM) which was the first commercially available computer playing a medley of songs: http://www.digital60.org/media/mark_one_digital_music/ http://www.digital60.org/media/mark_one_digital_music/