Vinyl LP pressing. Formula, Vol. 3 is the fifth studio album by Dominican singer Romeo Santos. It is the third installment of Santos' Formula trilogy following Formula, Vol. 1 (2011) and Formula, Vol 2 (2014). Musically, it combines traditional bachata with innovative fusions exploring and experimenting dance, tropical house, hip hop and pop. The album features several guest appearances by international stars such as Rosalía and Justin Timberlake plus guest appearances by artists of his natal Dominican Republic such as Toño Rosario, Lapiz Conciente, Ramon Orlando, Luis Miguel Del Amargue, Rubby Pérez, Fernando Villalona and Chris Lebron.