SWEET IS THE MELODY is a lovely waltz by Iris Dement, which you can hear at prairiehome.org

Other waltz tunes I like are:

Midnight On The Water
SOMEWHERE MY LOVE (LARA'S THEME) from Dr. Zhivago
MY FAVORITE THINGS
TUMBALALAIKA
DIE LORELEI
THE ANNIVERSARY SONG (by Al Jolson et al., based on a waltz by Ivanici)
Ah, Mari! (Oe, Mari!)
ROSIN THE BEAU
COME BACK, PADDY REILLY
MOUNTAINS OF MOURNE
TRAMPS AND HAWKERS
UN CANADIEN ERRANT
Rozhinkes Mit Mandlen - Yiddish
FINJAN (or Hafinjan) -- Hebrew
DE COLORES
MY YIDDISHE MOMME
CIELITO LINDO
SCARBOROUGH FAIR
ALWAYS (Irving Berlin)
THE BAND PLAYED ON
Melody Of Love
Norwegian Wood
NOW IS THE HOUR / HAERE RA
SUNRISE, SUNSET
Matchmaker
Goodnight, My Someone

and some we may not think of as waltzes:
DARK AS A DUNGEON
The Star-Spangled Banner
HOME ON THE RANGE
TAKE ME OUT TO THE BALL GAME



I believe the Austrian title for the "Over The Waves" (Loveliest Night Of The Year) waltz is "Donauwellen," though the composer (not one of the Strausses) escapes my recollection.