Estévez received degrees from the École Normale de Musique de Paris (Advanced Composition), the Sorbonne University of Paris (Ph.D. in Sociology), the National Conservatory of Music, Quito, Ecuador (Classical Guitar and Music Theory), and the Central University of Ecuador (Architecture).
  Lives and works in Louisville, Kentucky, USA.

Attended analysis seminars at the Conservatoire National Supérieur de Musique de Paris; electro-acoustics and computer music at the Centre Européen pour la Recherche Musicale in Metz; and pursued graduate studies in musicology (ABD) at the Sorbonne University. Taught composition, orchestration, musical analysis, computer-assisted music (1985-94), and classical guitar (1970-80), at the National Conservatory in Quito.

Founded the Ecuadorean Festival of Contemporary Music and the series Music of our Times and directed them from 1985 to 1994.
Served as visiting composer-in-residence at the University of Louisville (1994-1997) and as composer-in-residence at Spalding University, Louisville (1997-2002).

Latest commissions: Ensemble SurPlus, Germany, Festival Internacional de Música Sacra in Quito; Institute for New Music of Freiburg, Ensemble Aventure of Germany, Nieuw Ensemble of Amsterdam.