I confess from the start that this reply is more anecdotal than useful. But on the other hand, as suggested by the previous reply, what you are asking for is, pretty much, the original karaoke machine. These days, what people think of as karaoke is something with a specially recorded backing track, and a screen that gives you the lyric guided by a helpful bouncy ball. As fellow Brit contributors to this forum will know, for many years in the UK, the most popular television magazine programme about technology was a program called 'Tomorrow's World'. I well remember when they first demonstrated the Karaoke machine, when it was cutting edge technology. And the original Karaoke machine did exactly what you are asking for. You could put any commercial recording you happened to have into the machine, and it was clever enough to analyse the recording, take out the top line, and leave you with the backing. And in the demonstration on the television program they used, yes you guessed it, ol' blue eyes, singing, yes you guessed it, that song. The program finished with the presenter belting out with real gusto that immortal line that perhaps is the definitive statement of what the Karaoke machine is all about, and is why the Japanese man who invented it must never, ever be forgiven:
Can I join in the off-topic fun? Rob - you are going to have to start charging for your language consultancy services. Were you aware that these words also have etymologically common source with the words engine and engineer as well?
engine
c.1300, from O.Fr. engin "skill, cleverness," also "war machine," from L. ingenium "inborn qualities, talent," from in- "in" + gen-, root of gignere "to beget, produce." At first meaning a trick or device, or any machine (especially military); sense of one that converts energy to mechanical power is 18c., especially of steam engines. Engineer "locomotive driver" is first attested 1839, Amer.Eng.
