Another item found in a builder's skip, and one that has proved very useful, though not for any of its own sounds.  It's a HORRIBLE thing ( I can't bring myself to call it an 'instrument' ): cheaply built, noisy as hell, very difficult to programme, blessed with possibly the world's worst repertoire of preset naff synth voices AND...the icing on the cake...a singularly nauseating bip-bop drum machine.  I hate it.

Farfisa TK-100 keyboard

HOWEVER... it does have two very useful attributes - a 5-octave keyboard and a DIN socket for MIDI output.  Hence, it has been a valuable tool for controlling software synths and emulators.  Consequently, I've used this keyboard on virtually every one of the re-worked songs in Playlist 1.