I am a professional musician & audio engineer, have been playing for 20+ yrs and have played on dozens of recordings done in Canada, Nashville, Memphis and Chicago. I can add some electric bass to your song. If you are looking for Flea-style super-funky slapping, that is not what I do. But if you are looking to add a real bass to your rock, country, blues or pop song, you're in the right place. See also my gig for upright bass for a more old-school sound.
Basic rate is for one verse & chorus of the tune, if you've recorded to a click track you should be able to copy and paste at will. If you've got other parts e.g. bridge or middle 8, variations etc. just purchase the extra to cover that.
I would ask that you credit me in the liner notes/online and let me know about it if the project is for sale or is for an ad, jingle etc., just so I can add it to my resume and link to it from my page.