What are the alikes and differences of a Sonata and a Rondo?

Answer 1

The word 'Sonata' can either refer to a piece for one or two instruments in several - usually three - movements (eg a Beethoven piano sonata or Mozart violin sonata - for violin and piano) or it refers to a specific 'sonata form' structure of writing a piece of music. This is usually:
1 Exposition - usually two (sometimes three) often contrasting themes are stated.
2 Development - these themes and fragments of them or varied, modified and otherwise cleverly 'developed' by the composer.
3 Recapitulation - the theme are reinstated more less as in the exposition but perhaps in different keys, maybe in reverse order and perhaps with a little more modification before reaching the conclusion of the movement.
Sometimes a composer will add a short 4th section called a 'Coda' to end the movement which, although usually related to the thematic material heard earlier in the movement, will take on a different character (perhaps a faster section or a hushed slow section).

Rondos are much simpler in construction. A main theme is stated and then restatements of it are interspersed with contrasting episodes so the form looks like ABACABA etc. It's up to the composer how many episodes he wants to insert and some rondos can be quite long and complex. However, they should always end with the 'A' section and, quite often, a little 'Coda' (as above) to finish. Rondos are most commonly found as the last movement of a three- or four-movement piece (mostly likely a concerto) but this is not always the case. There are some 'concert rondos' that are 'stand alone' pieces.

Hope this doesn't read too confusingly and that it helps explain.

Answer 2

Sonata form implies Theme 1 - Theme 2 - development - recapitulation - coda. A Rondo implies Theme 1 - Theme 2 - Theme 1 - Theme 3 - Theme 1 (there can, in fact, be as many intermediate themes as the composer desires, but theme 1 always comes in between each new one)

A sonata is a piece (usually) in three movements, for solo instrument or a duo. The first movement is usually in sonata form and the last can, but need not, be a rondo.

Answer 3

Rondo is one part from a Sonata.
http://en.wikipedia.org/wiki/Sonata_rondo_form