Ostinato is a 8 letter English word. It's valid Scrabble word worth 8 points. It's valid Words with friends word worth 9 points.
You can make 206 anagrams from letters in ostinato (ainoostt).
1875-80; Italian: literally, obstinate Latin obstinātus obstinate
You have made just such a mistake in your otherwise beautiful Basso ostinato.
In my opinion, your Basso ostinato should be written in 3/4 or 6/4 time, but not in 5/4.