In King Oliver’s version of St. James Infirmary, it seems that all the improvisation occurs one after another once the melody has been played through once. It is clear that the first bars are not improvisation, as more than one instrument is playing the same melody. However, once it is just one lead instrument with accompaniment, the lead instrument will play their own solo, which is not necessarily perfectly in time with the tempo. In some cases, there is syncopation occurring so that the solo does not seem so stiff and premeditated. In contrast, A Cab Calloway’s version does not feature all the solos back to back. Additionally, there is much less improvisation throughout the piece. Instead, there are many unison lines, such as the trumpet melody after the vocals. The only solos that exist are a saxophone solo preceding the vocals and a trumpet solo near the end. The saxophone solo, compared to King Oliver’s solos, is much more frantic feeling and seems heavily out of time. This however could also reinforce the feeling of spontaneity. It is unclear if the single trumpet line at the end is a solo or not, since compared to the earlier saxophone solo, it is much more composed and has a more predictable series of steps and leaps.