Cappella and Heavy metal

Cappella adverb - Without musical accompaniment.

Heavy metal and cappella are semantically related In some cases you can use "Heavy metal" instead a noun "Cappella".

Heavy metal noun - A metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead).

Cappella and heavy metal are semantically related in harmonized topic. You can use "Cappella" instead a noun phrase "Heavy metal".