I agree. Beatles songs are great for this. But I would say don't stop after learning a few simple songs, always keep learning more. one new song each week maybe. Keep in mind that most of the musicians whose music you are learning probably learned this way as well. of course, if you want to learn classical or play like Coltrane, you'll need to learn the theory.
The very first Swift question has a partially incorrect answer. It says that "var array2 = array1" creates a copy of array1. But it's incorrect because a copy isn't actually created until one of them is mutated.
It's also Dorian and Phrygian without the 2 and 6. Plus you can use it in other keys, the A Pentatonic in the key of Bb is lydian, in G it's dorian, in C it's major, etc..