I've talked a lot on this site about this attempt at a national Irish Catholic hymnal in Irish Gaelic. Well, now you can see it for yourself. It's actually been online at archive.org since May of this year, but incompetent cataloguing has hidden it from us. (Apparently, someone can't deal with accented vowels in a title or an editor's name.)

http://www.archive.org/details/dtadidirseanagus00nadu

There are actually a few items in this hymnal (a couple of poems by "Torna", a 1924 poem by Douglas Hyde (aka An Craoibhin Aoibhinn), and three or four pieces of music by Professor O'Dwyer) which may still be in copyright. Also the hymnal SATB arrangements by O'Dwyer may be under copyright. I don't really know Republic of Ireland copyright law, though, so they may have come into the public domain (for US purposes) back in the day. (Since it's not in English, there are some US states out West which definitely have all the text out of copyright; but it hasn't been tested on other circuits. One of those weird law quirks.)

If I were you, I'd download a copy now, though. It's an extremely rare book, it's never been reprinted, and the binding of mine is falling apart even though the paper is still good.

The rest of the poems and tunes are all solidly public domain. It's been a pain in the butt to establish this to my satisfaction, since the bibliographic info is all written in Irish. (My copy has a Nihil Obstat and Imprimi Potest from 1933 _glued in_ at the front, so I guess it took the publisher a while to get technical support from the chancery. This may be part of why the sales were so low. Five years... sheesh! A death sentence! The publisher must have been mailing out Nihil Obstats to his old customers!)

The hymnal divisions are Maidin (Morning), Trathnona (Evening), Aidbheint (Advent), Nodlaig (Christmas), Corghas (Lent), Aoine an Cheasta (Good Friday), An Casg (Easter), Cingcis (Pentecost), Domhnach na Trionoide (Trinity Sunday), An Comaoin Naomhtha (Common of Saints), Danta Naisiunta (Patriotic Hymns), Feile Colmcille (St. Columcille's Day), Feile Brighde (St. Brigid's Day), Duan Posta (Wedding Hymn), Duan Seachtmhaine (Week Hymn), Danta Molta De (Songs of the Praise of God), Danta Gradha agus Creidim (Hymns of Love and Belief), Danta Gearra (Short Hymns), and some poems not set to music. There's not much in the way of Marian or saint hymns, because the hymnal editors meant to leave that for later. Most of this stuff is more devotional than liturgical, which is probably why there's so many hymns for Morning and Evening.

The tempos are given in half-notes. (No idea why.)

The font is an old Irish-language font, used to appeal to people out in the country who were used to reading books that were handwritten in uncial. (Yes, there was still a lot of that going around, even in the early twentieth century.) The dots above letters indicate that an h is added after that letter. (C with a dot = ch.) They use every period of Irish, and the book predates the post-WWII government spelling changes, so read warily!