Tempo Leveling Control

Most modern audio systems come with a volume leveling control that lets you reduce the difference between soft and loud sounds. There should be a tempo leveling control also, to help mitigate the annoyance of listening to a very badly performed piece of classical music where the performers WILL NOT stay in tempo. I'm listening to tchaikovsky's piano trio now, and while there should certainly be some rubato, ritardandos and accelerations to be expressive, this is completely out of hand the way they're doing it. It changes tempo from line to line and it's horrible.

The audio system must sense the "beat" in the music, and it must scan ahead and detect whether the music is about to go slower or faster than the established tempo, and compress or expand the future music stream so as to deviate less or more from this tempo, depending on the settings by the user.

The audio player must recognize changes in tempo that are *really* changes in tempo, e.g. the music literally changes from allegro to adagio. This should be doable because the main symptom the control is trying to fix is gradual accelerations and decelerations that are unwanted.

Thank you.