Music education (electric bass) icon needed for online course

Want to win a job like this?
This customer received 29 icon designs from 13 designers. They chose this icon design from Amhar619 as the winning design.
Join for free Find Design Jobs- Guaranteed
Icon Design Brief
Hey there! I run an educational electric bass site named Become A Bassist (becomeabassist.com/blog) and I need an icon for a new online course.
The course is called Bass Lines On The Fly and it shows bass players how to create bass lines at a jam session, rehearsal or gig and do it at the drop of a hat without sheet music or previous rehearsing/practicing the song.
The audience for the course is mostly older bass players who played bass when they were younger, but then quit playing. Then after raising families and having careers, they picked bass up again later in life.
Important: these are majority hobbyists - not people who necessarily want to be rockstars. They're more likely to want to play music with their son or their local blues jam session than play Madison Square Garden.
Here are my brand guidelines:
https://docs.google.com/document/d/1loDyMXUVz1ugSi-Ar8jtIZh5kPwQzeJekipzhL6YTkA/edit?usp=sharing
And I've also attached 3 existing icons from 3 existing courses. The one with the bass neck is the course about technique, the ear one is an ear training course and the 3rd one is all about groove.
All the previous icons used that bass clef (the swoopy thing with 2 dots), but you don't necessarily have to include that as part of this icon. However, it should use the same light blue (#0a6dcf) and should be roughly in the same 'family' as the existing icons. I'm not quite sure how to visually communicate the promise of the course in an icon, but I'm definitely open to ideas.
Cheers,
Luke
P.S. No wings please.
Look and feel
Each slider illustrates characteristics of the customer's brand and the style your logo design should communicate.