A lyrical poem resembles a musical composition in that it is rhythmic and has a "musical" sound, such as rhyme, alliteration, consonance, etc. Since early in the twentieth century, lyric poems either followed the traditional form of exhibiting rhyme and meter or they were free verse or "open form." Free verse poems may be rhythmic but are not metrical, following a regular beat and line length. Free verse poems also eschew end rhyme but may have a rich music of vowel and consonant sounds. The contrast between traditional and rhythmic poems is seen in the differences between poems by Robert Frost (traditional) and T. S. Eliot (free verse). Frost said that writing free verse poems was like playing tennis without a net. Eliot said there is a "logic of the emotions" that does not need to be confined to traditional forms.
The lyric is generally a short poem which deals overwhelmingly with emotion, most often love, and the personal feelings of the poet. It is therefore a subjective form of poetry, unlike other major forms such as the narrative or dramatic. Often the lyric follows a regular metrical and rhythmical pattern.
Originally the lyric was a form of poetry in Ancient Greece, designed specifically to be accompanied by the lyre (from which the word 'lyric' is derived). In succeeding ages, as the lyric spread all over Europe it no longer required musical accompaniment but the form retained musically expressive qualities. It popularity in English has fluctuated over the centuries, flourishing in the Rennaissance period but declining in the eighteenth century and then seeing a marked revival once more in the Romantic era, where subjectivity and intensity of feeling in poetry was valued above all else. This has continued in modified form up until the present day.
Although its exact from may change from age to age and from poet to poet, as a vehicle for expressing subjective feelings the lyric remains a popular poetic form.