A singer can be contracted, or hired, to sing in a wedding band, but if she contracts, or comes down with, the flu, the band will contract, or shrink.
As you can see, contracted has a few different meanings. Contract can refer to getting an illness or disease. Most things contract, or get smaller, as temperatures lower. Contracted can also mean an agreement, usually in writing, for a service to be rendered. In Mafioso terms, hit men are contracted to kill a specific person or persons. This is one type of contract that you want to avoid at all costs.
