The students should be given time to cover the information they have gathered and play a recording or two of the composer's music. It is suggested that students have at least 10 minutes for the presentation and another 5 - 10 minutes for musical examples. You may specify different expectations for the oral presentation. Maybe you don't mind them dressing down rather than dressing up. Do stress good volume and diction when speaking.
Eye contact is also an important skill to develop.
If they practice the presentation enough, eye contact will be easier to accomplish. Connect the knowledge your students gain through these webquests to their musical study in your classroom. If you use this in a band class, read through or perform an arrangement of a composition by this artist. If you use this in a Cultural Survey course, examine paintings, sculpture, dance, architecture, and plays of the time in more detail.