It's been a _long_ time since I performed professionally, but when I did my set was about one third my own stuff. Never did "covers" as such though; _interpretations_ on the other hand....

If I loved a song, if it really meant something to me, then I'd want to perform it and use _my_ emotions to deliver to the audience the meaning the song had for me, ie my own "take" on it. Sometimes my take was subtle; just a different emphasis in the lyrics; and sometimes much more radical - from very different arrangements from the original to "tweaking" the lyrics and melody.

I don't really see any other way to learn new rhythms, progressions, keys, harmonies, _except_ by doing something new to you. Otherwise you just get stuck inside the limits of your skill and knowledge. Other people's tunes expanded the vocabulary of what I could do, and eventually that vocabulary would be incorporated in my own work.

As for artists that do only their own stuff, well, there's Greats who do/did that; guys like Harry Chapin or Jim Croce for example, and Greats who do very few of their own numbers; such as Maggie Holland or Christy Moore - which just goes to show the truth of what's been said in this thread - the Performance is the thing - not the composer. The Singer/Songwriters I've admired are the ones who put as much effort and craft into their performance as their composition. (BTW: rather than singer/songwriter I've always preferred the term Harry Chapin used; Songsmith; for people who put effort into every aspect of their craft including the performance).

But most of the artists I know of who stuck exclusively to their own stuff were pretty mediocre - if they'd put other people's stuff into their set then their own work may have suffered from the comparison!

I remember the example of one Irish girl who wrote and performed what I called "music to test drive Prozac to" who for some reason decided to put her interpretation of Christy Moore's "Ride On" on her 2nd album (with Davy Spillane on pipes) - and BANG! It was possibly the most spine tingling awesome version ever done. Huge air-time hit on Irish Radio too! But it didn't half make her own stuff look like crap; I wasn't the only one who bought her album just to tape Ride On off of it!

Wrinkles