Yes, they sounded refreshingly new.
I got this in an email;
Rarely in the Beatles is the bIII chord used together with the minor relatives ii, vi and iii. Instead, bIII is most often used together with I, IV, V and bVII. A simple but acceptable picture of "traditional harmony," which mainly uses the chords of F - C - G - D - A in the key of C, in other words I, IV, V and two chords in the G direction; while rock harmony in the same key will use the chords of Eb - Bb - F - C - G, that is, I, IV, V and two chords in the F direction.
The only place in the Beatles's music where these 5 chords and none other are used is the instrumental section of "Here Comes The Sun." In chord progressions like C - Eb - F - G ("Please Please Me"), C - Eb - F ("Sgt. Pepper") and C - Eb - Bb ("Everybody's Got Something To Hide, Except For Me And My Monkey"), a couple of these 5 chords are used. They seem to be combined any which way, as usually with the given that the tonic is used often enough, and in such places, that it really is made to feel the 'resolution'.
Even during the Beatles's heyday there were songs written using these 5 chords and none others. Two examples are Wilson Pickett "(In The) Midnight Hour" and Creedence Clearwater Revival "Proud Mary". Both songs use the progression ( in C major) Bb - G - F - Eb - C in their introductions. A later example, among many others, is "Middle Of The Road," The Pretenders in 1982.
This leads to interest of a newer kind of mode-like sound built on the five chords I - bIII - IV - V - bVII, and in many cases implying that other chords (except bVI) are not present in parts using these with the bIII chord being important, as I, IV, V and bVII are used in other ways too.
None of this would seem to help the casual listening experience, but it's part of the appreciation for students and especially performers who need to learn 'what's going on'. And of course this is just a sliver of what's going on and what's significant (either different, new, clever or violating convention).
What might someone who plays by ear expect in music by the Beatles and other, stylistically closely related music?
Regarding form: that the song has a verse, that most often will feel like "home," and that probably will be the first form part (after the intro, if there is one) to be heard. In relatively few cases, the first form part to be heard (after the intro) will be the chorus. Furthermore, a chorus and/or a bridge that have a contrasting function, often (in songs in major keys) beginning on one of the relative majors, and most probably occurring after two verses (bridge or chorus) or after two pairs of verse-chorus (bridge).
Regarding harmony: that songs in major are a lot more common than songs in minor; that there will be an easily discerned tonic, or a chord that feels like "home"; that chord progressions to a very large extent will be built on I, IV and V, and in lesser degree on their relative minors vi, ii and iii and the bVII and II chords. Chords other than these will either
The Harmonic Language of the Beatles
follow traditional functional harmony (i.e. chords in the dominant direction, plus the minor subdominant and its relative major) or imply a new "modality," using the major chords I, bIII, IV, V and bVII.
This means that the music of the Beatles and their contemporaries has its starting point in traditional functional harmony, but a functional harmony where the limits for what is allowed are slowly being expanded. Chords close to the tonic on the circle of fifths are combined totally freely; more chords in the subdominant direction appear in the music; and the II chord can be used in the traditional way, but also with a new freedom. In rock music, functional harmony has started a slow explosion, that continues to this day. In the 1990s, it is possible to compose using progressions like (in C major) C - F#m ("Fade Away" by the English group Blur, from their CD "The Great Escape," 1995) or C - A - F - C# - B ("In Bloom" by the American group Nirvana, from "Nevermind," 1991) as the foundation of a song, without being too extreme. The Beatles and their contemporaries very seldom used that kind of chord progressions.
In such latter-day cases it obviously gets more and more meaningless to think in terms of functional harmony: the explosion of functional harmony is completed.