There are two versions of Good King Wenceslas for alto saxophone here: An easier solo arrangement of Good King Wenceslas for sax in the key of C (concert E flat), and a version to play along with other band instruments in the key of A (concert C). Select the image below for a printable PDF of the melody. The Good King Wenceslas Band Play-Along page has more versions of this song, so you can play it with other woodwind and brass instruments. The string arrangement of the carol is also in the key of C, so you can play it with violin, viola, cello, and bass. Visit the Good King Wenceslas lead sheet page which features the carol in seven different keys. On that page you can find an instrumental range or key that is more suitable for you, or print an arrangement that allows you to play along with other instruments.
Good King Wenceslas for alto sax, band play-along version: