From an early age, Alberto's parents detected a keen sensitivity and interest in music, especially during prayers sung in synagogue, and decided to send him to stay with his uncle in Smyrne (now Izmir).

At the conservatorio, Hemsi was taught by internationally acclaimed professors such as Bossi Pirinello (composition, harmony, and counterpoint), Galli (orchestration), Pozzoli Delochi (theory and solfeggio), and Giusto Zampieri (music history).

There, he met his wife, Myriam, and in 1927, the pair joined his extended family in Egypt, where he worked as the musical director and conductor of the choir at the Eliyahu Hanavi Synagogue in Alexandria.

Hemsi proceeded to dedicate more than 17 years of his life to collecting traditional chants throughout the former Ottoman Empire, particularly in Smyrne, Salonica or Thessaloniki, Rhodes, Istanbul, and Alexandria.

In addition to the Coplas Sefardies, Hemsi composed numerous other works for a variety of ensembles including orchestra, string quintets, choir, cello, and piano.

He found work as music director in synagogues as well as a solfeggio teacher for Sephardic liturgy at the École Cantoriale du Séminaire Israélite de France (S.I.F.)