There is certainly a difference between successful songwriters; Lennon, McCartney, Richards, Anka, Bon Jovi, etc...and musical poets such as Dylan, Cohen, Downie. It may be a coincidence, but poets can rarely sing very well...Downie has a decent voice though.
Interestingly, Poet Laureates never seem to get recognized by the Nobel committee.
For the record, the poet laureate for the USA is Juan Felipe Herrera. For Canada, it's George Elliot Clarke and for the UK, it's Carol Ann Duffy.
Peter: for South Africa, it's Keorapetse William Kgositsile.
Household names all...oi vey
(I knew the Canuck...the others I had to google)