Yes, it's absolutely the case for Lennon and McCartney, since they didn't give rough ideas to George Martin to fill in; they specifically wrote the exact melodies for half the instruments involved and exactly how to play them.
You could argue that Harrison and Starr always deserved some of the writing credit, since they often determined their parts, and I wouldn't actually disagree with that -- though Lennon and McCartney were kinda control freaks, so I'm not sure how much leeway was actually given. When they started bringing in extra instruments, again, there is arguably some extra credit to be given to Martin and others, but Lennon and McCartney were still strongly directing what was to be played.
For what it's worth -- and this is going to get me hated even more than my popstar-skepticism -- I don't really like the Beatles that much. But it's transparent that they did more than Taylor Swift because they were specifically and precisely writing the melodies for the instruments being played.
You could argue that Harrison and Starr always deserved some of the writing credit, since they often determined their parts, and I wouldn't actually disagree with that -- though Lennon and McCartney were kinda control freaks, so I'm not sure how much leeway was actually given. When they started bringing in extra instruments, again, there is arguably some extra credit to be given to Martin and others, but Lennon and McCartney were still strongly directing what was to be played.
For what it's worth -- and this is going to get me hated even more than my popstar-skepticism -- I don't really like the Beatles that much. But it's transparent that they did more than Taylor Swift because they were specifically and precisely writing the melodies for the instruments being played.