Features

Allows Space Age music to be used while Space Age is installed, even when disabled.
Allows tracks per planet to be enabled for other planets.
Allows setting weights for tracks from different planets.
Allows hero tracks to be played as normal tracks.

Compatibility

List of planets - A space separated list of planets to use as source or target
Weights - A matrix of weights, according to the order of the list of planets above.
Each row represents a target planet
Values in each row represent the weight of tracks from other planets
Values are separated by spaces
Rows are separated by commas
A partial mapping is allowed; Unfilled rows will not be modified, unfilled columns are considered 0.
Empty rows are allowed, but a single space has to be used, rather than subsequent commas
List of planet to use hero - A space separated list of planets whose hero tracks can be used as normal tracks

For example:

Planets: nauvis space vulcanus fulgora gleba aquilo
Weights: 1 1 1 1 1 1, ,0 0 1 0.5
Heros: fulgora

Will result in:

Nauvis playing tracks from all planets.
Nauvis will also play Fulgora's hero track as a normal track.
Vulcanus will play its own tracks normal, and will also play Fulgora's tracks at 50% of its normal weight.
Other planets and space are not affected.
Interlude tracks are converted to main tracks, to avoid tracks appearing too much.

Default settings:

Planets: nauvis space vulcanus fulgora gleba aquilo
Weights: 1 1 1 1 1 1
Heros:

Plays all music (other than hero tracks) on Nauvis, at a balanced amount. Space Age is not required to be enabled for this to happen.