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.
This arrangement for marimba can be performed on 4.3 octave marimba or larger. The notes in parentheses are intended for a 4.3 octave marimba. 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.