If you look into who a bard was from a historical standpoint, bards were the ultimate entertainers. The writing about Leliana and Varric in DA2 follow the functions of bards in the medieval period. They weren't just singers, but story-tellers and evolved into basically spies who could share or even sell secrets. Their talents were in entertainment. For Leliana it was both singing and story-telling, though with Varric we'd hear more about his grand tales and risque books. If your bard was more of a story-teller, writer, or even a playwrite, it may work if your backstory has someone who can't sing. Though, can your Cousland play an instrument? Or does he not have any musical talent? Perhaps over time he could learn the lute from Leliana, since she would teach her bard skills to others.