Fran, In all the years of my teaching and playing I do not feel I can do any song justice until I've heard the song played by the original composer.
I would rather see (In pop type of music)
1-Happy
2-Sad
3-lively
4-Slow with feeling
These I can understand.
So my rule is to do the best with what they give you knowing that till I've heard the song there I can not play it as the composer wanted played.
On the good side, there are many times when my interpation was better than the original. Then again I would think that. ha ha

Do you remember the song, "Breaking up is hard to do" It was recorded in different tempos. I felt the slow version was the best.

Music is fun, John C.