GUEST, when I said "especially if you already have at least 2 good octaves," I was referring to voices (like mine) that have a 2 1/2 to 3 octave range but with maybe only 2 octaves that are strong and full enough to be "solo quality."   Adding 3 octaves would give you a range of 5 1/2 to 6 octaves - something I've never encountered.