Lyrical poetry, or lyric poems, is a category under which various types of poems fall. Sonnets are lyric poems as are elegies and odes. Each of these types of lyric poems has its own structural guidelines, for instance, English sonnets are composed of fourteen lines comprised of three quatrains (four line stanzas) with a rhyming couplet comprising the last two lines. Lyric poetry is distinguished by four principla points.
First, in lyric poetry, the poet (or sometimes speaker other than the poet) is expressing her/imself personally. Second, the poet is expressing personal thoughts and feelings. Third, lyric poetry does not tell a story, has no narrative, as opposed to poems like The Rime of the Ancient Mariner, which are narratives telling stories. Fourth, lyric poems are musical in composition as the original ones were meant to be accompanied by the lyre (the word lyric is derived from the word lyre), hence there is musical rhythm and there may be a chorus.
Dryden's lyric poem "Song for St Cecilia's Day" has all of these features. Written in iambic rhythm (soft, stressed, soft, stressed, etc) and changing between a tetrameter and trimeter (e.g., stanza 3), the song is a personal expression of the poet. In it, Dryden is singing the praises of the power of harmony and music ("What passion cannot Music raise and quell?"). He uses emotional language (excites, pains, pangs, passion) and he expresses deep thoughts about the topic ("Notes inspiring holy love"). It is clear that he is not telling a story but rather expressing himself. Remembering that lyric poetry is written as a song, hence the title, there are rhythmic changes when the song switches between tetrameter and trimeter. Also this lyric poem ends with a Grand Chorus, as is suited to a song.