When I talked about using Stride in improvisation, I referred to the use of Alternate Bass. Sometimes a song will have several consecutive measure of the same chord. To keep from playing the same octave over and over, musicians will substitute the fifth of that chord as the alternate bass. So, G is five notes up from C, it is the alternate of a C chord. It is also the third note of the C triad/chord, so it is easy to find.
Marches commonly use this technique and Sousa is the ultimate as a composer of marches. Let’s look at his “Semper Fidelis” march. In measure 11 he starts with
the tonic “C” and uses the alternate bass “G” on the 3rd count. Because he just used “G” on the third count in measure 12, he moves immediately to the alternate bass for the 1st count in measure 13. Also, I point out he steps down in measure 16 and walks up to the same Alternate bass in measure 17. This is a fine example of creative use of octaves for the improviser. Though faster songs often use stride with alternate bass, you can still use it with slower songs and combine it with chord inversions for slower songs like “Silent Night.”
“Semper Fidelis” by John Philip Sousa