Clifford Brown - 1954

‘Joy Spring’ certainly lives up to its name. A fairly straightforward harmonic language lets the melody shine. It’s a great tune to work on creating smooth horn-like phrases on the piano. 

Joy Spring
Joy Spring

The following examples offer some analysis of the changes. Example 1 is firmly in the key of F Major. 
Example 2 moves between Gb Major and A Major. 
Example 3 moves from F to Eb to Gb  and back to F.

These key centres are, for the most part, established enough to consider them modulations.

Example 1
Joy Spring
Example 2
Joy Spring
Example 3