If Ye Love Me, by Thomas Tallis, is an English Anthem that was first published in 1560, and perhaps composed circa 1549.
This piece can serve as an introduction to your students of music from the Renaissance Period. The polyphony within forces students to listen and count.
El Testament d'Amelia (Amelia's Will) is a popular Catalan folk song. This arrangement is a good choice for an intermediate level pianist, or as a more lyrical program selection for the more advanced performer.
Ave Verum Corpus is a motet composed by Mozart in 1791 to celebrate the feast of Corpus Christi.
Francisco Tarrega (1852-1909) was a Spanish composer and classical guitarist regarded by many as "the father of the classical guitar." Adelita is a mazurka originally composed for guitar by Tarrega. The mazurka originated in Poland and was popularized by Frederic Chopin.
The tempo is indicated as Lento, but seems to work better at a faster tempo. The audio file here is at 80 bpm. However, this piece should not be performed metronomically, but rather with a more rubato style.