When we speak, Charlotte Brimmer has just released her new single 'Brighter Without You', her second since signing to Columbia Records. 'I'm currently in Hamburg doing promo and really enjoying the sunshine in this lovely city,' she says. In March, the 21-year-old Dundonian announced details of a new single, 'Do Not Disturb', with its heady pop soundscape signalling a new direction for the singer-songwriter. 'Releasing music for the first time in almost three years was so liberating and playing headline shows has been amazing. I'm feeling excited and optimistic!'

'Brighter Without You' is the darker of the two singles, but maintains that shimmering pop backdrop, with introspective lyrics and a colourful melody speaking directly to feelings of heartbreak and disappointment. 'I just try to be honest in my songwriting,' Brimmer notes. 'I'm trying to figure things out and grow an understanding of why people are the way they are. Both songs are coming from a similar line of thought. I wrote "Do Not Disturb" in Berlin, a few months after writing "Brighter Without You". I'm so pleased that other people have been able to relate to the music and listen to the songs in their tough times.'

Having performed since her early teens, Brimmer has been working hard to hone her sound, progressing hugely and finding her voice in the process. 'I feel like I'm more confident in my ideas,' she explains. 'I've had the pleasure of working with lots of producers in Scotland and in London, and then in Stockholm, Berlin and Nashville. It's been great to pick up different tips from every session and it's helped me to understand the things I definitely don't like and the things I want to focus on in my songwriting. My main strength has always been in my melodies, but in recent times I've focussed on improving my lyrics too, and all of those experiences have helped.'

As well as working and performing around the world, Brimmer has had some particular highlights over the past few years, which include playing the 3D Festival for the opening of V&A Dundee, supporting BRIT winner Tom Walker, and, more recently, playing Hampden Stadium for the Scotland v Jamaica women's football match. Not long ago, Brimmer also undertook a schools tour in her home city and beyond, where she spoke to pupils, played some of her music and held a Q&A session. The primary goal of that tour was to encourage the next generation of musicians to think about picking up an instrument and potentially pursuing a career in the music industry.

'I loved it!' she says when asked about the experience. 'I wanted to play some shows in schools because I wanted to inspire young people to make their own music as I think it's such a positive way to express your feelings. I especially wanted to encourage young girls to go for it, whatever their aspirations might be.'

This summer, Brimmer will be supporting The Proclaimers in a series of massive shows, but also has some other exciting dates coming up, including her Fringe by the Sea gig alongside indie favourites Idlewild. 'I love that part of Scotland, it's so beautiful on a nice day. The audience can expect me and my band to give our everything to make sure people feel entertained. It's the first time I've headlined a festival so I'm really excited to do that. We might even throw in a wee cover …'

So with two singles now out in the world and more inevitably in the pipeline, is there a full-length album somewhere on the horizon? 'It feels weird to say I've written hundreds of songs but I'm not quite sure when that will become a whole album. I think all the music I've ever written has storytelling at its core. "Do Not Disturb" and "Brighter Without You" are definitely exploring the questions I have from childhood into teenage years, and I'm still looking for answers. It feels good to let it all out.'

Be Charlotte @ The List By The Sea Party, Lighthouse Spiegeltent, North Berwick.