Tagus an easy piano duet 4-hands composed around 1820 by Hector Berlioz (1803-1869).
Pages: 2 pages both hands, 1 page prima, 1 page seconda, 1:15 min, with downloadable mp3 for audio help.

Skylark is an American popular song with lyrics by Johnny Mercer and music by Hoagy Carmichael, published in 1941.
Here is an arrangement for Flute (plays the melody) and Piano duet.
With lyrics, guitar chords and melody line. With downloadable simple mp3 for practice the flute.
Flute early intermediate. Piano advanced Intermediate.
Five pages (4 pages both Flute and Piano, 1 page Flute), 2:20' min.

Serenata Rimpianto Op.6 No.1, by Enrico Toselli, Count of Montignoso (March 13, 1883 January 15, 1926).
For Violin and Piano duet. With downloadable mp3 for audio help.
Violin Early Intermediate, piano Intermediate

Six pages (3 pages both Violin and piano, 1 page Violin part, 2 pages Piano part), 3:20' min.

Romanesca is a 16th century tune for Violin and Piano duet.

Violin Early Intermediate, Piano Intermediate. With downloadable mp3 for audio help.

Eleven pages (5 pages both Violin and piano, 2 page Violin part, 4 pages Piano part), 6' min.

Total: 11 pages.

The pleasure of love, is a classical French love song written in 1784 by Jean-Paul-Egide Martini (17411816).
Here is an arrangement for easy piano duet 4 hands.
With downloadable mp3 for audio-help, 2:28 min