The most popular Beatle song was Twist and Shout written by Phil Medley and Bert Berns. It wasn't released as a single because Lennon and McCartney didn't write it.
Lennon and McCartney
This crazy idea led to the belief that groups and singers had to write their own songs!
They were only signed because Decca Records overlooked the Beatles. So Keith Richards and Mick Jagger had to start writing songs.
The Rolling Stones
In any business you don't need to be original, you just copy something else.
The Music Business
A songwriter is a person who creates all or part of a song. So they can be the person who wrote the words or the composer of the tune.
These are people who write the words.
A person who crates the tune.
This usually applies to someone who writes down the music that was composed.
He was a band leader and an arranger. He wrote down the music for the members of his band to read and play.
This is obviously someone who sings.
InstrumentalistSomeone who plays a musical instrument.
Singer/SongwriterThis is someone who writes their own songs and sings them too.
Modern MusicTo get signed to a major record company you need a lot of luck!
What is expected is in my opinion impossible. You need to be absolutely brilliant at all of the following: