Martha, is a romantic comic opera in four acts by Friedrich von Flotow (1812-1883).
Here is the celebrated theme from act II - Last rose o f Summer (Thomas Moore traditional Irish melody), easy to early intermediate, 3 pages, 75 bars, 3 min.
With downloadable mp3 for audio help.

A sacred song (7) medley for piano solo first published around 1890.
Early intermediate to intermediate level.
With melody line, with downloadable mp3 for audio help.
Pages : eight (8) pages, 8:40' min.

Just As I Am,  Charlotte Elliott (1789-1871)Rock of Ages, Augustus Toplady (1740-1778)
Nearer My God to Thee, Sarah  Adams  (1805-1848)
How Gentle Gods Commands, Philip Doddridge (1702-1751)
Majestic Sweetness Sits Enthroned, Samuel Stennett (1727-1795)
Flee as a bird, Mary Dana Shindler (1810-1883)
Onward Christian Soldiers, Sabine Baring-Gould (1834-1924)

La Favorite by Gaetano Donizetti (1797-1848) is an opera based on a French drama with origin to a Spanish work: a young man's adventures with a beatiful lady who turns out to be the favourite of the king. Here is the theme from act IV for piano solo. Easy to early intermediate, 2 pages, 34 bars, 2:30 min. 
With downloadable mp3 for audio help.

La Truite by Franz Schubert (1797-1828).
For intermediate piano solo, with downloadable mp3 for audio help, 2 pages.

Two works: C.Weber Valse, and Gavotte by G. Handel.
With finger position suggestions. Easy piano, 4 pages.
With downloadable mp3s for audio-help.