On the collector's edition of Jeff Wayne's Musical Version of The War Of The Worlds, there are four tracks featuring guitarist Chris Spedding counting bars, apparently all through the entirety of the concept album, probably per track.

I would assume it has to do with the cadence and progression of the entire piece, but the hilarity with which this is done, as exemplified by those tracks, makes at the least the method to achieve this seem a little ludicrous.

An example:

What is the purpose of this bar count?