Stack an ordinary major triad on top of a dominant chord's guide tones (just the 3rd and 7th) and the triad's own notes become the chord's tensions — a rootless, pianistic way to play an altered or extended dominant without naming a scary chord symbol. Which triad you pick decides which tensions you get. Type a dominant chord, pick a structure, and see (and hear) exactly what lands where. For the plainer voicing family this extends, see Jazz Voicings.