I assigned Cat Groups to apply different royalty rates across the Catalogue. However, a Release contains Tracks from different Cat Groups. How can I pay this correctly without having blended rates?

Release sales are allocated to the Release rather than the individual Tracks, and are reported to the Contract based on the terms set for that Release.

If a Release contains Tracks belonging to two or more different Catalogue Groups, each with different sales terms, the recommended solution is as follows:

Create a unique Cat Group specifically for the mixed Release.
Assign this new Cat Group only to the Release, not to the individual Tracks.
Create a new term in the Contract for this unique Cat Group, applying a proportional royalty rate.

This methodology ensures that the correct blended rate is applied to the Release sales.

Calculating the Proportional Rate

If, for example, your Release consists of seven Tracks, where:

Three Tracks are reported at a 5% royalty rate, and
Four Tracks are reported at a 2% royalty rate.

The royalty rate for the new term would be calculated as: (3x5% + 4x2%)/7 = 3.29%