It may be useful to select a range of contrasting pieces in terms of their mood/emotion that all fall under the recital theme. 

In the same vein it would also be suitable to select similar moods of pieces where the time periods are different - the contrast here may come from the different view of each period. 

You may have similar pieces the contrast itself may come from the exploration of the different themes in either verse or prose format and the impact that that has.