Billie Eilish’s early calling card, ‘Ocean Eyes’, was written by her brother Finneas about an old girlfriend. It was only as an afterthought that he considered asking his kid sister to sing it. The rest is pop history – and billions of music streams.

Finneas and Billie are equal partners on Eilish’s two studio albums. So it’s surprising just how far he departs from her baroque sound on his debut solo record. Where Eilish’s output is a slow riot of cybernetic sturm und drang, on Optimist Finneas is all about the heartfelt twang.

He sounds very much like a Gen Z Chris Martin at moments. Elsewhere, there is something of the pop-processed rock of One Republic or a zillion-selling Death Cab For Cutie. It’s catchy and heartfelt – yet utterly removed from the music O’Connell makes with his sister.

O’Connell has stated that he wants people to know immediately what he is singing about. That’s in contrast with the ambivalence that defines Eilish’s pop. The approach gives his songs an immediacy, as demonstrated by ‘A Concert Six Months From Now’, in which he mourns a failed relationship by reflecting on a show he and his ex had planned on attending.

Despair meanwhile curdles to anger on ‘The Kids Are All Dying’, a commentary on social media virtue signalling, while Finneas unloads on the celebrity industrial complex on ‘The 90s’ (he wishes could go back to 1997, when nobody had camera phones and the internet didn’t rule our lives).

Finneas has a crisp, expressive voice and a knack for glossy angst. Optimist is, it is true, unlikely to cause the tectonic plates of pop to shift, as they did when he and his sister released Happier Than Ever over the summer. Nonetheless, it packs its own subtle punch.