Eternal Triangle was written by saxophonist Sonny Stitt. This song was featured on trumpeter Dizzy Gillespie’s 1957 record Sonny Side Up. The recording features Stitt and his contemporary tenor giant Sonny Rollins battling it out with phenomenal solos followed by a fierce trading session. Eternal Triangle is essentially a Bb “Rhythm Changes” tune, with a re-harmonization on the bridge. You can also check out the intro on the original recording as this can be played as well.