A while a pal told me about an indie kid who was working beside him. He claimed to love music but hated harmony (!??) We both found it rather intriguing ….It meant missing out some major pieces in the pop music cannon. Louvins, Everleys, Beatles, Beach Boys, Mamas and The Papas, The Byrds, The Jackson Five…you get the picture.

For me it’s always been the thing that can change a performance from good to sublime. Sometimes it’s just one voice adding that third to the melody line. Then sometimes it’s more. I was a huge fan of CSN& Y growing up and in those pre youtube days I used to spend time imagine how they went about their business on stage. Off all the groups I have never seen live they are the one I wished I’d seen most.

This Friday we are going to celebrate harmony singing because of our very special guests. It’s always a joy to welcome live talent to Studio One at PQ. It’s a wonderful space and being in the room as musicians do their work is a joy for me. This week we welcome The Mermaids.

It will be their first session for us and also a session for BBC Introducing, the scheme which supports new artists to gain a wider audience.The Mermaids are Ellen and Rosie MacFarlane who came to our notice because their mother was kind enough to alert us to their debut album. Intriguingly recorded in one day it is a great calling card. Rosie plays ukelele and Rosie plays guitar and together they sing in joyous, beautiful harmony. I saw therm a few weeks back at King Tuts and I was very impressed. I suppose we’ve grown used to how good siblings sound together, but it’s great to be reminded again – especially when these young girls come from Galloway in Southern Scotland. They are twenty and sixteen years of age and I think you will be amazed at how assured their performance is and how strong their own songs  sound. You are also going to like the cover song they are planning to do.

So – we’ll play other Sisters – the Secret ones, celebrate a brilliant vocal track from Noah Gundersen, hear something new and excellent from Blue Rose Code and  hear what Dolly Parton has done next. We’ll also say Happy Birthday to an artist we love very much ………recognise him?

There will be lots of nice surprises that would only only be spoiled if I told you everything now. So hear it all for yourself on Friday from five past eight on BBC Radio Scotland.