The most significant roles she played at the Latvian National Opera are Adalgisa (Bellini's Norma), Carmen (Bizet's Carmen), Olga (Tchaikovsky's Eugene Onegin), Bradamante (Handel's Alcina), Hansel (Humperdinck's Hansel and Gretel), the Third Dame (Mozart's Die Zauberflöte), Mary (Wagner's Der fliegende Holländer), Maddalena (Verdi's Rigoletto), Fenena (Verdi's Nabucco), Amneris (Verdi's Aida), Suzuki (Puccini's Madama Butterfly), Cherubino (Mozart's Le nozze di Figaro), Dorabella (Mozart's Cosi fan tutte), Missis Growse (Britten's The Turn of the Screw), Matilda (Kalsons's The Prodigal Son), The Angel (Rubinstein's The Demon).
There are a lot of vocally-instrumental forms in the singer's repertory, among them Bach's Magnificat, Johannespassion, Matthauspassion, Marcuspassion, Mess h-moll, The Christmas Oratory, Handel's Messiah, Stabat mater by Vivaldi, Pergolesi, Rossini and Dvorak, Mozart's The Coronation Mess, Villa-Lobos' Magnificat, Te Deum by Bruckner and Kodaly, Mors et Vita by Gounod as well, as the music of Latvian composers (Magnificat by Ingm.Zemzaris and by Im.Ramiņš, A.Grīnups's Requiem, A.Maskats's Symphony and Salve Regina, Symphony and Mass by R.Liede, B.Skulte's Daugava etc).
A.Bigaca's repertory of chamber music is wide and rich. Tchaikovsky, Rachmaninoff, Schumann, Schubert, Volf, and Metner can be mentioned among her favourite composers. She sings Latvian classical music and a range of modern Latvian composers' songs, dedicated to her.
The singer performs in Latvia and abroad (United Kingdom, Germany, Sweden, Poland, Russia, Netherlands, Venezuela, Trinidad, Tobago, Switzerland, Australia, USA, Lithuania, Estonia, Israel, Hong Kong, France, and Canada.
The singer is a prizewinner of the J.Mediņš Vocal competition (Latvia, 1989, 1992). She was awarded with the Great Latvian Music Award (1995) and the Latvian Music Award (2009).