In terms of chords and melody, Drunken Sailor has complexity on par with the typical song, having near-average scores in Melodic Complexity and Chord-Bass Melody and below-average scores in Chord Complexity, Chord-Melody Tension and Chord Progression Novelty.
Drunken Sailor is written in the key of E Dorian. According to the Theorytab database, it is the 2nd most popular key among Dorian keys and the 31st most popular among all keys. The E Dorian scale is similar to the E Minor scale except that its 6th note is a half step higher (C♯). Chord progressions in Dorian have a characteristic sound due to the major quality of the chord built on the 4th scale degree. See the E Dorian Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!