These are exercises for developing facility and fingerboard knowledge on the electric bass, but they could apply to any fretted instrument tuned in 4ths, or a mandolin that you turned upside-down. Right now they’re available in D, but maybe I’ll expand the harmonic options available one day. If you have questions about these exercises, can’t figure out how to best transpose them, or you have questions about how to extend the ideas contained here, drop me a line.