WordNet (r) 3.0 (2006):

Psalms
    n 1: an Old Testament book consisting of a collection of 150
         Psalms [syn: Psalms, Book of Psalms]

Easton's 1897 Bible Dictionary:

Psalms
   The psalms are the production of various authors. "Only a
   portion of the Book of Psalms claims David as its author. Other
   inspired poets in successive generations added now one now
   another contribution to the sacred collection, and thus in the
   wisdom of Providence it more completely reflects every phase of
   human emotion and circumstances than it otherwise could." But it
   is specially to David and his contemporaries that we owe this
   precious book. In the "titles" of the psalms, the genuineness of
   which there is no sufficient reason to doubt, 73 are ascribed to
   David. Peter and John (Acts 4:25) ascribe to him also the second
   psalm, which is one of the 48 that are anonymous. About
   two-thirds of the whole collection have been ascribed to David.

     Psalms 39, 62, and 77 are addressed to Jeduthun, to be sung
   after his manner or in his choir. Psalms 50 and 73-83 are
   addressed to Asaph, as the master of his choir, to be sung in
   the worship of God. The "sons of Korah," who formed a leading
   part of the Kohathite singers (2 Chr. 20:19), were intrusted
   with the arranging and singing of Ps. 42, 44-49, 84, 85, 87, and
   88.

     In Luke 24:44 the word "psalms" means the Hagiographa, i.e.,
   the holy writings, one of the sections into which the Jews
   divided the Old Testament. (See BIBLE.)

     None of the psalms can be proved to have been of a later date
   than the time of Ezra and Nehemiah, hence the whole collection
   extends over a period of about 1,000 years. There are in the New
   Testament 116 direct quotations from the Psalter.

     The Psalter is divided, after the analogy of the Pentateuch,
   into five books, each closing with a doxology or benediction:

     (1.) The first book comprises the first 41 psalms, all of
   which are ascribed to David except 1, 2, 10, and 33, which,
   though anonymous, may also be ascribed to him.

     (2.) Book second consists of the next 31 psalms (42-72), 18 of
   which are ascribed to David and 1 to Solomon (the 72nd). The
   rest are anonymous.

     (3.) The third book contains 17 psalms (73-89), of which the
   86th is ascribed to David, the 88th to Heman the Ezrahite, and
   the 89th to Ethan the Ezrahite.

     (4.) The fourth book also contains 17 psalms (90-106), of
   which the 90th is ascribed to Moses, and the 101st and 103rd to
   David.

     (5.) The fifth book contains the remaining psalms, 44 in
   number. Of these, 15 are ascribed to David, and the 127th to
   Solomon.

     Ps. 136 is generally called "the great hallel." But the Talmud
   includes also Ps. 120-135. Ps. 113-118, inclusive, constitute
   the "hallel" recited at the three great feasts, at the new moon,
   and on the eight days of the feast of dedication.

     "It is presumed that these several collections were made at
   times of high religious life: the first, probably, near the
   close of David's life; the second in the days of Solomon; the
   third by the singers of Jehoshaphat (2 Chr. 20:19); the fourth
   by the men of Hezekiah (29, 30, 31); and the fifth in the days
   of Ezra."

     The Mosaic ritual makes no provision for the service of song
   in the worship of God. David first taught the Church to sing the
   praises of the Lord. He first introduced into the ritual of the
   tabernacle music and song.

     Divers names are given to the psalms. (1.) Some bear the
   Hebrew designation _shir_ (Gr. ode, a song). Thirteen have this
   title. It means the flow of speech, as it were, in a straight
   line or in a regular strain. This title includes secular as well
   as sacred song.

     (2.) Fifty-eight psalms bear the designation (Heb.) _mitsmor_
   (Gr. psalmos, a psalm), a lyric ode, or a song set to music; a
   sacred song accompanied with a musical instrument.

     (3.) Ps. 145, and many others, have the designation (Heb.)
   _tehillah_ (Gr. hymnos, a hymn), meaning a song of praise; a
   song the prominent thought of which is the praise of God.

     (4.) Six psalms (16, 56-60) have the title (Heb.) _michtam_
   (q.v.).

     (5.) Ps. 7 and Hab. 3 bear the title (Heb.) _shiggaion_
   (q.v.).