UST Singers founder and Conservatory of Music academic staff member Asst. Prof. Fidel Gener Calalang Jr., delivered guest lectures and joined as an international jury member in choral festivals in Spain and Taiwan.

Calalang facilitated a lecture on "Banal: Philippine Sacred Choral Music in the Concert Repertoire." This special lecture was part of a series hosted by the 2023 Taipei International Choir Festival and Competition in collaboration with the National Taipei University of Education in Da'an District, Taipei.

He was also invited as a guest speaker at the 5th Annual Conducting Workshop organized by the Unió Musical D' Alaquàs, held at the Alaquàs Conservatory of Music in Alaquàs, Valencia, Spain.

At the 32nd Certamen Habaneras y Polifonia Totana, Calalang served as jury member at the Auditorio Municipal Marcos Ortiz in Murcia, Spain. The national competition, which specializes in the singing of the traditional song form, "habaneras," featured various choral groups from the different regions of Spain. 

Calalang has led the University of Santo Tomas Singers through its 36th International Goodwill Concert Tour titled 30th Encore: Harmony through Time, the UST Singers' 30th-anniversary tour. The choir's latest international sojourn saw them traveling in Germany, Spain, Italy, Belgium, and Taiwan. The tour lasted six weeks with 22 standing ovation concerts held in different cities in Europe and Taiwan.