A static backing track to practise over a Cmaj7 chord. Pick a feel, put it on, and play.
Backing track
What to play over this
Start with the scale itself, then colour it with the chords and modes it contains.
Scales and modes
C Major ScaleG Major ScaleE Harmonic MinorF Melodic Minor #4E Gypsy MinorF Gypsy MinorC Harmonic LydianF Harmonic LydianC Messiaen M3A Messiaen M3F Messiaen M4E Messiaen M7F Messiaen M7C Jazz MajorG Jazz MajorC Jazz Major b3G Jazz Major b3C Jazz DominantD Jazz DominantG Jazz DominantA Jazz DorianD Jazz DorianE Jazz Melodic MinorAm pentatonicDm pentatonicEm pentatonicBm pentatonic