From TolkienBooks.net:

Songs for the Philologists is perhaps the rarest and most difficult to find Tolkien-related publication (although Sir Orfeo could also state a claim). It began life as a set of duplicated typescripts prepared by E.V. Gordon in 1922-1926 for the amusement of English students at Leeds University. These typescripts included verses by Gordon and Tolkien, as well as other traditional songs in Old and Modern English and a variety of other languages.

In 1935 or 1936 Dr. A.H. Smith of University College London, formerly a student at Leeds, gave a copy of one of the typescripts to a group of students to print at their private press. The group included, amongst others, G.T. Ilotson, B. Pattison and H. Winifred Husbands. The booklet was printed in hand-set type as an exercise on a reconstructed wooden hand-press.

Dr. Smith later realised that he had not asked for permission from Tolkien or Gordon, so the completed booklets were not distributed. University College was bombed during the Second World War and the press, and most of the stock of printed items, were lost in the ensuing fire. Evidently some copies of Songs for the Philologists survived - those retained by Smith and the students who printed them. The number that survived the fire is unknown, but is undoubtedly very small - according to one report "more than thirteen".