Originally from Manila, Karlene was granted a full scholarship to the Philippine High School for the Arts as a voice major before she graduated Magna cum Laude from the University of the Philippines (UP) with a Bachelor's degree in Music in Voice. She continued her training at the Royal Northern College of Music in Manchester and on the Advanced Performer's Studio opera course with The Associated Studios in London. She has performed extensively throughout the Philippines and has featured on television and radio. Karlene won second prize in the National Music Competition for Young Artists (Philippines) and represented her country at the Eurofolk International Festival in Erba, Italy and Puchon International Folk Art Festival in Korea.
Opera courses she attended include the Rencontres Musicales Internationales in Belgium, Junge Opera Schloss in Weikersheim, Germany and Accademia Bel Canto in Austria where she performed in masterclasses under Christa Ludwig and Angelika Kirchschlager.
In concert, she was the soprano soloist for London Beethoven Project for Beethoven's 9th Symphony, and in Bruckner's Te Deum with the Philippine Philharmonic Orchestra, premiered two original Filipino compositions for soprano and orchestra with the Metro Manila Community Orchestra and performed major roles in the University of the Philippines Opera Season with the UP Orchestra. Karlene was a member and soloist of the two-time European Choral Grand-Prix winners, the Philippine Madrigal Singers, and sang in their concert tours of Europe, Russia, US, Japan and Korea.
Her operatic roles include Musetta 'La Boheme' (New London Opera Players), Adina 'L'Elisir D'Amore' (UP Concert Season), Adele 'Die Fledermaus', Mercedes 'Carmen' and Pamina 'The Magic Flute' (Brent Opera), Lola Markham 'Gallantry' (Camden Fringe Festival), Donna/Female Officer/Lisa Morritt 'The Face' (Grays Inn), Susannah 'Susannah' (UP Concert Season), Governess in Britten's 'The Turn of the Screw' at the London Horror Festival and Marzelline for the New London Opera Players production of Beethoven's 'Fidelio' in Kent.
In July 2014, she made her role debut as CioCio San in Opéra de Baugé's production of 'Madama Butterfly' in France and most recently sung the role of Despina in Opéra de Baugé's Cosi Fan Tutte' in August 2015.
Future performances in 2016 include CioCio San for Secret Opera's Madama Butterfly and Miss Wordsworth in Albert Herring with Opéra de Baugé..