Tomorrow is the feast of St Francis of Assisi, and the YouTube channel of Corpus Christi Watershed has just recently posted a nice recording of the Sequence used by the Franciscans at his Mass, here sung by Andrea Leal. It is attributed to Thomas of Celano, who is also believed to be the author of the Dies Irae. The text is too long to conveniently include in this post, but is available here in both Latin and English: http://www.liturgialatina.org/dominican/sequence_francis.htm. The chant notation can be seen here: http://archive.ccwatershed.org/media/pdfs/20/09/23/02-02-37_0.pdf.