When soloing over any chord type, there is always more than one scale option. This is particularly true of dominant chords, where alterations are likely to occur This is demonstrated in the following examples in the key of C, but it is essential to transpose these ideas to all twelve keys once you understand them.
If you are soloing over a C7, C9 or C13 chord, your first scale choice would probably be C Mixolydian and the various dominant arpeggios derived from it. The scale degrees under the notation are numbered in relation to the chord tones of a C13 chord.
By harmonising this scale, the following arpeggios can be derived from the C7 chord tones.
Any or all of these arpeggios can be used when soloing over a C dominant chord. Learn the line shown here and then make up some of your own.