Oh for a summer's dignity
but oh, alas, 'tis not for me
the times have waned
and with them I
and but dreams remain
of times gone by
The ode is written for an occasion or on a particular subject; it is somewhat lyrical and can be put to music, but often is merely lilting, hinting at a rhythm. It has some form of rhyme scheme and meter, nothing strict, nothing overly complicated.
It is typically a dignified or serious piece, though in recent times this has been twisted sarcastically -- still meditative or noble in phrase but not in subject.
For more information on this or other forms, see these links