Mostly Autumn are a rock band from York, UK. Their music contains elements of progressive rock, hard rock, folk-rock and celtic rock, and has included flute, violin, whistles and Uilleann pipes alongside traditional rock instruments. Their music has changed and evolved over the years although much of their work retains a strong 70s classic rock feel. The band was formed in 1997 by guitarist and vocalist Bryan Josh and has undergone a great many lineup changes over the band's history, too many to list in full. The earliest lineup of the band featured Heidi Widdop on lead vocals, but by .