"What makes you different from ­anyone in here? What makes you stand out from the crowd?" The ­questions posed by ­tonight's ­opening song, An ­Ordinary Life, are ­pertinent: how did this ­agreeable but ­unextraordinary Glasgow songwriter manage to carve out a career in which her achievements include elbowing ­Radiohead off the top of the album chart with her first release? The ­definitive ­answer didn't present itself at this ­low-key gig, designed to ease ­Macdonald back on to the live circuit after a year spent writing the follow-up to her 2007 debut, which sold 3m ­copies worldwide. She was charming and ­capable, and she had glammed up in black sequins, but there was still ­little to ­distinguish her from legions of equally able but less ­successful singers.

Her entrance was announced with a splat of synthesised bagpipes – cute touch – and then it was down to ­business. Macdonald's gusty tone and timbre put her somewhere between KT Tunstall and Kirsty MacColl, ­predisposing her to belt out ­vigorous, straightforward pop-rock. Fans of her debut, This Is the Life, will find the new album, A Curious Thing, to their liking – tracks previewed tonight, such as This Pretty Face and Spark, stick to the same forthright template. This Pretty face adds a folky Scottish twang to the mix, while the acoustic intro to No Roots gives Macdonald's clear voice room to breathe. It was an older song that was most vivid, though: Let's Start a Band, which exhorts ­someone to "put a ribbon round my neck and call me a libertine", was a stomping hoedown tarted up with ­wah-wah guitar.

What lingers is her spirit and ­determination, which may be qualities more associated with a Girl Guide than a pop star, but clearly do the job for ­Macdonald and three million fans.