Both pieces remind me a lot to the galant style, for example:
- The use of repeated motives as in b1-2, b11-14 etc (first sonatina)
- Short motives
- A very simple harmonic language
- And a very 'light' (i don't know what word should i use hahaha) contrapunctus
I don't that if you wanted your piece to sound like that but you should bear that in mind.
But there are some contradictions with this style:
- Exagerated dynamics
- An irregular feeling of tempo in b4
- Usually, in classical/galant style the whole musical phrase should be 8 bars long (4 + 4) or something in that proportion; your phrases are 5, 3 and 2 bars long.
- As @Henry Ng Tsz Kiu said, you must follow the sonata form if you want your piece to be called sonatina
A tiny guide to sonata form:
Sonata form is actually a variation of binary form |: I V :|: V I | (used in baroque dances, check bach BWV826 or cello suites for references!)
Sonatas consist of two differenciate themes (Mozart, usually make the first one more lyrical and the second one more rythmical, check Sonata Facile), but the second theme must be in other key (usually the dominant key). Then, both themes are fractured into motives and combined together in the development, this section is full of key changes, progressions, pedal notes etc..., after that, both themes apear in the original key.
For example:
- Ravel sonatina
- Clementi sonatinas
- Grieg's holberg suite, 1st movement
- Mozart's sonatas
- Beethoven sonata no.3
Note, sonatas are usually the first movement of suites!
I hope i helped you 🙂
- Samuel
EDIT: The b theme is longer than the first theme, inside B, there are B1 - transition full of tension - B2 or coda