One Morning in May, is a 1933 jazz standard by Hoagy Carmichael and Mitchell Parish.

Guitar Solo. Intermediate. Jazz, Jazz chord soloing, melodic Jazz.

With standard notation and Tablature (TAB).

Pages : Two (2) pages.

O mio babbino caro ("Oh my dear daddy") is a soprano aria from the opera Gianni Schicchi by Giacomo Puccini. The aria was first performed on 14 December 1918 at the Metropolitan Opera in New York.
Here is an arrangement for Violin and guitar duet. Early Intermediate.
With  guitar tablature. With downloadable mp3 just for audio help. With lyrics.
Pages:  Four pages score and parts (two pages both violin and guitar, 1 page violin part, one page Guitar part), 1:18 min.

O Christmas Tree ("O Tannenbaum") is a German Christmas song. Based on a traditional folk song, it became associated with the traditional Christmas tree by the early 20th century and sung as a Christmas carol.
For Guitar solo or Guitar and voice (classical guitar or acoustic guitar fingerstyle).
Easy to Early Intermediate.
With Tablature. With downloadable mp3 for audio help or sing along. With melody line. With lyrics.
Pages: two pages.

Nobody Knows You When You're Down and Out is a moderate tempo blues with ragtime influences,written by Jimmy Cox in 1923, with many recordings by numerous musicians as Bessie Smith and Eric Clapton.

For Guitar solo or Guitar and voice.
With melody line and lyrics.  With standard notation and tablature.

Early intermediate.
Pages: Four (4) pages.

Nightingale Rag by Joseph Francis Lamb (December 6, 1887 September 3, 1960).
A standard ragtime with classical elements.
For Classical Guitar or acoustic Guitar fingerstyle Solo.
With downloadable mp3 just for audio help.
With standard notation and tablature. With some fingering position suggestions.
Early Intermediate to Intermediate
Pages: Four pages (4) pages, 3:15' min.