Watch the Floating Sus Intro: Key of D online guitar lesson by Vicki Genfan from Acoustic Rhythm Guitar Cookbook
This is a progression that I created many years ago as an intro to the song "Landslide" (Fleetwood Mac). From a theory viewpoint, it's simply composed of variations of a V chord (A7), which makes the listener long for a resolution to the I chord (D). By continuing to play different versions or voicings of the A7 chord, we build tension, which is ultimately resolved by playing the rest of the song. Building and resolving tension are key components of songwriting and arranging.
In both studies, we'll work with slash chords. In the first study, we'll work with a beautiful fingerpicking pattern that we then embellish in the second study.