you're probably correct, there's no melody attached just a chordal backing. But I've just been thinking about it and yes from a previous study, I've seen augmented chords labelled as + 5...I just remembered now...Novalis wrote:I think it could also mean +5, so an augmented chord.
Have a look at the melody, maybe that can give you a clue about what exact chord to use.
Not a very nice way to not it anyway, though.
thanks,