Aal was born in Bremgarten, Switzerland, and was pastor there until 1529, then Leutpriester in Baden until 1536. At the collegiate church of Solothurn, he became preacher and choir leader in 1538. From 1544 to 1551, he was provost of the college of canons, where he died.
He is the author of the tragedy Johannes der Täufer (St. John Baptist), first performed in 1549 in Bern. The piece is a folk play in two days with four acts each. It includes burlesques, romantic scenes and satirical elements. Its satire derides all classes and the court as well as curiosity, passion for finery, loquacity and the art of seduction of women.