Queen's "We Will Rock You"/"We Are The Champions", Boston's "Foreplay"/"Long Time", and Alan Parsons Project's "Sirius"/"Eye in the Sky" are examples of this.

Queen's "We Will Rock You"/"We Are The Champions", Boston's "Foreplay"/"Long Time", and Alan Parsons Project's "Sirius"/"Eye in the Sky" are examples of this. It's almost strange to only hear one half of the pair, and in the case of Foreplay and Sirius, those are completely instrumental.