Four Old Geezers and a Valkyrie by Gordon Lawrie (ebook)

Romantic comedy set in Edinburgh. N=ewly-retired teacher Brian 'Captain' Reid faces a personal and financial crisis, having just discovered that half of his pension belongs to his ex-wife. While working in a cafe for extra cash, an old friend drops in and suggests he dredges out his guitar, unplayed for decades, and joins him and his brother for a jam session the following Sunday.

It turns out that Captain can not only still sing, he can write half-decent songs, too. Uploading a couple to YouTube, they turn out to be surprise hits. All they have to do now is to work out how to make money from them, which leads the 'band' into a whole new set of adventures...