Since its genesis in 1994, Celtic Connections has grown way beyond the expectations of its organisers and audience across Glasgow, Scotland and, indeed, the world.

During its 20 years, the programme has expanded and diversified to encompass a massive array of different ages, ethnic groups, creeds, philosophies and, most importantly, musical genres. As it stands now, the whole "Celtic" term has been stretched in so many directions that perhaps the festival has helped widen its very definition – at least as far as music is concerned.

If Celtic culture loosely collects the common history, language, music, art and literature of the north-western European areas of Scotland, Ireland, Wales, Brittany, Galicia and Cornwall, then this hugely respected annual shindig has delved further into the indigenous music of lands far beyond these, and fortunately brought them to our very own doorstep. Styles, techniques and ideas are swopped and fused each year, enthralling crowds and bringing previously polarised parts of the world closer together.

As the festival has developed, its introduction of Americana, jazz, world music and indie-rock has very much worked in its favour. For inquisitive musical minds such as mine, always searching for something new, one continually finds something interesting and exotic in the festival's programme. What's more, I believe it's healthy for folk players to move forward and incorporate new influences in their work, and for indie musicians to stop navel-gazing and inject more wide-screen inspiration into their art too.

As a teenage alternative-rock and indie fan throughout the 1980s and early 1990s, alongside my peers I baulked at the mere suggestion of Scottish traditional music. Always in need of a quick-fix guitar hit, a brash new beat and the empty rhetoric of another sneering rock messiah, we weren't interested in Scotland's musical heritage. It was all tartan tat and shortcake tins, set to fleeing fiddles and blaring bagpipes. It was something for older, teary-eyed generations and bewildered tourists. However, today we live in an age of rediscovery and reinvention of our own musical past. The "folk" tag is often blazoned as a badge of honour for a new artist, rather than something to be embarrassed about. Musicians increasingly feel the need to reconnect and learn about their ancestry and folk traditions, but express them in a fully modern context.

Not since the 1960s have music lovers yearned for such authenticity and rootsiness in the face of the super-charged, manufactured, mainstream machine. Yet while the rock and pop fads fluctuate, the unadorned, down-to-earth passion and musicianship of these global folk sounds continue to entertain a growing, hungry audience.

Without trying to be hip or cool, and with little artifice or pretension, Celtic Connections has shown itself to be the perfect platform to showcase this contemporary roots movement. In many ways, it has been ahead of the curve.

For the first couple of years, the festival passed me by, but then I began to take notice; not just because of its increasing size and popularity, but because of its broadening sonic church.

How much of this music is "Celtic" is debatable, but under such an umbrella term, it does all feel somehow natural and inclusive. This is, after all, an event that celebrated Robert Burns's 250th birthday with Sly & Robbie in an ingenious Jamaican take on the bard's work.

At the festival's inaugural year, select audiences were treated to live appearances by stalwarts of the scene such as Dick Gaughan, Battlefield Band, Aly Bain and Phil Cunningham. Twenty years later, in more than 250 events, you have the opportunity to witness Edinburgh hip-hop troupe Stanley Odd, whose rapper Solareye eloquently spits out his philosophies and diatribes in his own Edinburgh brogue and native tongue. If hip-hop is in essence the music of black America, then a group like this give it a definite "Celtic" twist. From the festival's origins until today, you couldn't find more disparate musical stylings.

In 2013, there aren't many events on the calendar where you can experience respected local indie tunesmiths such as The Pictish Trail, Olympic Swimmers and Washington Irving on the same bill as the "golden voice of Africa" Salif Keita or the Bulgarian State Television Female Vocal Choir who recorded Le Mystere Des Voix Bulgares.

One day you can enjoy the 1960s' Scottish trailblazers, Beatstalkers, the next some Ethiopian jazz from Mulatu Astatke or even the hollerin' rock'n'soul of Oklahoma's JD McPherson.

Although Celtic Connections may be aware of its limits, it pushes them continually and always seems to avoid pigeonholing. With such a collection of homegrown and international sounds – from new talent to established, legendary acts, using initiatives such as New Voices, Transatlantic Sessions and Hazy Recollections and branching out into theatre, film and educational projects – the festival is more than just an annual knees-up.

It has shown that it is definitely not blinkered, cliquey or narrow-minded, and as a result Scotland's cultural image has been boosted and bolstered immensely – all under this polymorphous "Celtic" tag.

It's a very brave move indeed to book a festival of any kind in Scotland during January, but to do so in such a well organised, focused and good-natured way deserves plaudits. For bringing that intimate, pub-session-type atmosphere to Glasgow's Royal Concert Hall and so much more, we salute you. Happy 20th birthday, Celtic Connections.

Vic Galloway presents on BBC Radio Scotland on Monday, 8.05-10pm (repeated Fridays, 10pm–midnight). Vic's Celtic Connections special is live on BBC Radio Scotland tomorrow with sets from JD McPherson, Washington Irving and Jo Mango. Contact Vic at and