“TK421,” from Lenny Kravitz’s 2024 album Blue Electric Light, is a vibrant funk-rock anthem bursting with energy and groove. Centered in E minor, it features driving basslines, syncopated rhythm guitar, and sizzling lead licks layered over a tight, danceable beat. Blending vintage ’70s funk with Kravitz’s signature modern rock flair, the track is ideal for guitarists who want to work on rhythmic precision, funky strumming, and expressive solo phrasing with a bright, energetic tone.