I study a lot of neurophysiology at university and what Okoie says is actually incorrect (though, I appreciate the inquisitiveness). Motor coordination is not dependent on the Corpus Callosum.
Motor co-ordination is dependent upon the motor cortex, cerebellum, and basal ganglia. Most people's brains are wired in such a way that the limbs on your right side are controlled by the left half of your brain and the limbs on your left by the left half of your brain (this is a slight oversimplification however). So you would say in psycho-babble that your right hand is controled contralaterally.
The corpus callosum is a major source of communication between the two Right and Left hemispheres. When you initially learn a motor task your brain is mostly dependent upon the Primary Motor Cortex Cortex and Cerebellum. But as that task becomes more practised a new (and much faster) neural circuit develops between the Primary Motor Cortex, Supplementary Motor Cortex, and Basal Ganglia.
If you learn HT first your brain automatically, because of its contralateral wiring, learns HS. However, lets say you learn a piece HT and never ever try to play it HS until it is learned very well, in other words you have learned to such a point that the basal ganglia and supplementary motor cortex have taken over. If you do this then it will be hard to play the piece HS. What has happened is your brain has actually "chunked" the piece into a entire unit to more easily retrieve it and process it faster. i.e. Your brain went from viewing your piece as two independent behaviours (i.e. a right hand behaviour and a left hand behaviour) into one single behaviour.
So to put it more simply, whether you choose to learn a piece HS or HT, initially, your brain sees the behaviour of performing as HS regardless.
This is actually the main reason I supposed learning a peice HS was unnessesary, but for obvious reasons I avoided the issue.