This example of the blues uses I-V-I over the Bb7 in measure 3, and Eb7 in Measure 5. This is a way to solidify the “home” feeling of the harmony, both for the I chord (Bb7) and the move to the IV chord (Eb7). This device provides a nice contrast to the more common scale based lines.
The blues is a great place to practice using I-V-I over short static harmonies of two bars or less, so check out the transcription to be sure you can see exactly how we are using this device.
This course is taken from 'Walk On: New pathways for walking bass lines' by Danny Ziemann. It comprises 62 lessons and over 3 hours of video and if you are an intermediate or advanced player it should be a great fit!