Even though classical music is downright heavy (it is the heaviest form of music, just ask Yngwie),
one bar of blues is actually about 1.79 Troy Ounces heavier than any classical bar of music.
This exception to the classical rule is due to classical gas being much lighter than cobalt.
However, speaking of light...
Easy-listening music such as that provided by the likes of Kenny G weighs nothing. Furthermore, it contains no karots and thus has no nutritional value for the ear, your cochlea is always hungry for something of substance, but the more you hear of this mainstream that belongs in the toilet-drain, the emptier you feel and thus crave more ... That is why it is so voraciously consumed by the masses.