Purple ukulele-wielding lady targets Invercargill retail workers with songs of pure joy

We all appreciate great service - but for one woman, a simple thanks is not enough.

Shirley Cranstoun is an amateur musician from Invercargill. Armed with her purple ukulele and a song book crammed with more than 200 ditties, she's been bringing her unique songwriting talent to local businesses as a special thank you for excellent service.

She calls it 'uke bombing'.

"Uke bombing is like flash mob for a single person, you go into a business and play them a tune or two," she says.

"It's just to show appreciation for businesses that have given good service or you think need cheering up."

She's played for Burger King, Caltex, the local supermarket - she's even uke-bombed the cemetery.

"Let's face it, a grave digger's job is not that flash, so when I uke-bombed the grave diggers at the cemetery they really appreciated it."

Ms Cranstoun's style of songwriting is reminiscent of Friends character Phoebe Buffay's iconic so-bad-they're-good tunes.

With titles like 'Plastic Bag Song' and 'I Lost My Sense of Humour Down the Toilet', Ms Cranstoun's YouTube channel - to which she uploads new music weekly - is equal parts hilarious, strange and sweet.

"I want my music to say 'life's too short not to have fun', and 'please don't take life so seriously, there's always somebody who cares and there's always light beyond the blue horizon'."

She takes inspiration from everywhere: politics ('Pregnant Prime Minister'), her family ('Aunty's Lament') or the reproductive habits of crocodiles ('Crocodile Capers').

"Often I'll wake up at two or three in the morning having a dream about something, and then I'll lie in bed and it will go round and round my head," she says.

"By five o'clock I've got to get out of bed and get that song written or I'll forget the words."

This might explain the surrealness of her online discography.

When sung in the middle of a Caltex service station or a supermarket check-out, the songs take on another level of whimsical wonder.

As employees look on in stunned silence and Shirley's thick southern Kiwi accent filled the forecourt with lyrics like, 'Here's a song of dedication to the service station that we know as Caltex', it's hard to imagine a better way to show your appreciation.

For Ms Cranstoun, that's what it's all about.

"I think people who work in retail or in the service industry don't get enough praise and don't get acknowledged enough or appreciated enough for the work they do.

"If you can leave somebody happy with a smile, where's the harm in that?"

We sent Newshub out on a 'uke-bombing' raid with Ms Cranstoun in Invercargill. Watch the video to witness the true wonder of her music.