The Odes compile some beautiful prayers from Scripture. A few of them are in the Book of Common Prayer’s Morning Prayer canticles.
Good information on the Odes is hard to come by, though. In part this is because they are generally not accorded the same status as, say, the Psalms. The NETS introduction to the Psalms, for instance, has:
One “book” not included in NETS, however, is Odes since it has dubious integrity as a literary unit, and, in any case, almost all of the individual Septuagint odes have already been included in their native setting in other books. The sole exception is Ode 12 in Rahlfs’ edition, the Prayer of Manasses, which for that reason has been separately appended to the Psalter.
*HT to a member of the Yahoo! LXX email group for the idea of the Odes as a sort of “little hymnal.”