I never put out a formula until i've tested them in the shop, the studio, and the stage. I had the rare opportunity to have folks like la Familia Valera Miranda, Septeto Nacional de Cuba, and Changüi Guantanamo test these renditions. Leave a note if you have any special requests. I make these with the expectation you are using a tailpiece. If, indeed, you are using a fixed bridge, please include that in the Notes/Additional Info box on the order form.