As this CD consisted of two slightly different bands I had to make sure that when switching between tracks the levels did not change.

http://www.robtoulson.rt60.co.uk/rt_docs/RT_CompilationMasteringLoudness_ARP2013.pdf

This PDF by Dr Rob Toulson gives a really good overview of mastering a compilation CD.

Fortunately for me, I was mixing both of the tracks and both bands a relatively similar. This meant that getting them to the same level was a lot easier.

I approached the mastering by making each band’s music as good as I could get it. I then referenced their level against each other. This made sure that even if the levels were out with other music they would be the same.