Service composition is an important part of developing Service-oriented Systems. There are two basic approaches for service composition. First, the developer identifies and searches for individual services that can be composed. In the second approach, the developer identifies the global input(s) and output(s) of the entire composition and searches for a composition with the best match. We propose a "middle of the road" approach, where we identify and search for "sequences of services", each of which is a consecutively executed service that appears within an existing composition stored in a database. Our approach utilizes a database containing Service-oriented Systems. The developer specifies a query containing functional and non-functional requirements in XML format. Then the query is used to search within the database for a sequence of services that matches the requirements. We show the results of an experiment that indicates our approach enabled subjects to find more executable compositions than a tool that searches for services individually.