There aren’t many labels in popular music that come with as many unspoken assumptions as ‘singer-songwriter’ does. As cultural archetypes go, it’s uniquely malleable and somewhat slippery – images are conjured both of introverted Moleskine-clutching creatives & street-busking dilettantes,  haunting cafés as they wrestle with personal demons. It’s a label that could be reasonably applied to artists across a broad spectrum of creativity/popularity/influence while still retaining its diagnostic value – Nick Drake and Ben Howard are both ‘singer-songwriters’ in some sense or another. There also tends to be a smuggled expectation among listeners that the songwriting of a ‘singer-songwriter’ will…