Alex Pastrana has worked as an arranger for different artists and different genres from jazz, pop, salsa, Latin music, chamber music, different formats from string quartet, Big Bands, Symphonic Bands, among others.

He has worked as an arranger for: Juancho Torres and His Orchestra, Los Alfa Ocho, Chabuco, Maria Escobar.

In the most recent album by Maria Escobar he directed the musical production where international artists such as Toquinho and colombian artists such as Adriana Lucia, Cabas, Chabuco and Los Gaiteros de San Jacinto participated.