Ninety minutes may at first seem a long period of time, but you will probably find that the time is filled up quickly. You will be able to use more audio-visual materials, and if you invite guests, you can give them a longer time than was possible in the shorter weekly report periods. You will want to present short scenes from several plays related to your topic. You will also present appropriate short musical cuts or selections. If someone in your group plays an instrument, now is the time to utilize that talent, even if just for some background music or demonstration of some basic basic technique or aspect of an instrument germane to your topic.
Variety is valuable.
The most important need is to organize the time carefully. If one or more people organize one segment, others can assist with necessary technical support for that unit. What at first seems a great deal of time to fill can become too little. Don't, for example, play many complete songs, or 10 songs in succession, or perform too-lengthy scenes from plays. Write out a sensible schedule and stick to it during the actual presentation.