Now, I know the terms "a capella" and "instrumental" are pretty incompatible, and to tell the truth, something like "Lyric-less" would fit better than "instrumental" in this case. Basically, I'm looking for a word that applies to songs that use the human voice more for the purposes of making notes than singing words, perhaps even imitating conventional instruments like violins or guitars (but not drums, I know the term for that: beatboxing).
For instance, I want a word that could be used (for example) in place of my made-up word "Accapellental" in this example sentence:
Smoove McGroove is a great Accapellental artist.