It's a fact:

in 2014 there is still nothing to compare with the annual South By South West sensory bombardment of interactive, film and music festivals. For the 12th time in a row, I'm here in Austin, Texas to immerse myself in the music extravaganza, and yet again I'm overwhelmed and overawed by the sheer diversity of what's on offer for a full five days and nights. My ears are ringing, my nose is sunburned, my head is sore and I've had a total of about 10 hours sleep this week. And yet it's been a total blast. But within the maelstrom, you must be content in the knowledge that you merely scratch the surface of what has been scheduled. You would need several lifetimes to experience it all.

SXSW (as it's more compactly known) has changed radically since it began as an antidote to the East and West Coast US music business mafia back in 1987, and stood as a beacon of independence and DIY spirit in a cold, corporate industry. Now it has been co-opted by the mainstream, branching out into film and the increasingly popular interactive festival. I heard a staggering figure that there are 50,000 paying delegates this year. This is big business we're talking about.

Austin now has an international airport, a Formula 1 track and its population has doubled in size over 20 years. It is now bigger than San Francisco and officially the 11th largest city in the US. It is a huge, commercial epicentre with Apple, Google, Dell and IBM offices. Business, movie and sports stars are moving here in their droves, due to it being a sunny, liberal, comfortable place to live, with less than 5% unemployment. Austin is a genuine US success story in a time of recession, and SXSW plays a big part in that.

Where else would you have such a range of polarised events? At interactive, there were live streamed Q&A conference calls from whistle-blowers Julian Assange and Edward Snowden; then Lady Gaga gave this year's keynote speech and performed a secret show at the music festival. I was actually handed an exclusive wristband for her show and, although tempted to watch her art-pop pantomime, I saw sense and handed it to an ecstatic fan who wept with joy at having the opportunity to see their idol in action. My good deed for the day ...

This year played host to big hitters such as Coldplay, Damon Albarn, Kanye West and Jay-Z. Even a reformed Spandau Ballet staged a comeback gig, following in the footsteps of Duran Duran who succeeded at SXSW last year. Who wants to see Spandau Ballet in 2014 remains a mystery to me, though. Then there are the legions of bands with ludicrous names such as Diarrhea Planet, Guantanamo Baywatch, Perfect Pussy and David Hasselhoff On Acid; all here to turn heads.

As the days fly by, time seems to stand still as tens of thousands of delegates, punters and music nerds are suspended in a blur of bands, booze and barbecue. During the day, the town is besieged by countless "unofficial" parties where record labels, brands, blogs and magazines host their favourite flavours of the moment. Then, as the sun sets, the "official" showcases begin and every conceivable venue comes alive with the sound of an estimated 2500 artists.

On Wednesday afternoon alone, I saw sets by Glasgow's post-punkers Casual Sex, 1980s indie throwbacks The Pains Of Being Pure At Heart and left-field singer-songwriter EMA, before attending Hamburg's Reeperbahn Festival party. In the evening, I enjoyed the shimmering pop of Ballet School and witnessed a rare performance by "Queen of Rockabilly" Wanda Jackson on the way to see the wondrous, eccentric St Vincent. From there I popped into the Arts & Crafts label showcase ahead of being pummelled into submission by German proto-metallers Kadavar. I finished my evening with a soulful, solo set by Angelo Moore, frontman of the legendary Fishbone. That may give you some idea of the breadth and depth of what's possible to see if you stay on your feet long enough. It is a smorgasbord and everyone's SXSW is different.

On Thursday, like the rest of Austin, I heard the tragic news of the senseless deaths of two innocent revellers and the injuries of many more, caused by a drunk at the wheel of an out-of-control car. A hush descended on the festival as it fell into shock. But the show must go on, and on it went.

Scotland is represented here in large numbers once again, and Friday was our day. Creative Scotland helped fund a wide selection of different groups to come here. As the costs of flights, accommodation and visas are high, unsigned or lower-level acts need a financial helping hand to step onto this global platform. It is simple investment in an artist's future, and the possibility to connect with a new audience is massive.

As I write, I'm fresh (possibly the wrong adjective) off stage from this year's Showcasing Scotland event at a venue called Latitude 30, which is annually remodelled as the "British Music Embassy". It hosts a dozen different curated shows by the likes of BBC Introducing and NME. Our epicurean audio feast opened with a glorious, heartfelt set by that fragile, fractured troubadour Withered Hand. Dan Willson's songs now soar and his band filled the stage, counting a certain King Creosote in the ranks for these US shows.

Neil Pennycook has an astounding voice. Under his Meursault alias, ably abetted by his electric guitar and a trusty duo on bass and drums, he showed the Texans why his stock is continually rising at home with an impassioned set that suited the power-trio formula perfectly. Having helped pay for their visit to SXSW and consequent East Coast tour with a crowd-funded, kickstarter campaign, the band's confidence was very much in evidence as they steamed through songs from their previous releases and the forthcoming I Will Kill Again album.

One of this year's runaway success stories is the aforementioned Casual Sex. Joining a long line of bands with daft names, their music is anything but. Blending post-punk, disco, dub and krautrock shapes into their addictive indie racket has seen them play all over town for various pioneering publications and booking agencies. Tonight they delivered a razor-sharp performance and took the plaudits in their stride.

The youngest act on the bill took to the stage next. Honeyblood are a female duo in love with grunge and indie-pop from the early 1990s; and although the influences shine through, their songs are strong, containing polished, poisoned poetry on love lost. With a faint twang of country and sweet lead vocals, they proved they were more than capable of rocking Austin and worthy of their new deal with FatCat Recordings, also home to the next band to take the room by the scruff of the neck.

We Were Promised Jetpacks are veritable veterans of SXSW now, having attended the festival three times before. This year it is simply part of an American tour, but their audience here far outnumbers their fanbase in the UK. SXSW is really where they first connected with an audience who have taken their dark, emotive, visceral indie-rock to their hearts. Now augmented by a new member on extra guitar and keys, their sound is even more powerful than before. Judging by the new songs, Jetpacks could easily be our next alternative rock breakthrough.

As headliners, Young Fathers are stunning. Here is a band I can confidently say are one of the buzz acts of the entire festival, and from tonight's performance you can see why. I've been championing their twisted, tribal hip-hop for years and it's great to see others catching up. In a whirlwind of limbs, they thrashed around the stage in a blaze of intensity, bringing tracks from their debut album Dead to life. This is dynamic, modern music that shows what young, creative, multicultural Scotland is capable of. And the world is paying attention. The whole night was a triumph.

There are two musical movies from Scotland here for the film festival as well. God Help The Girl has already won plaudits for Stuart Murdoch from Belle & Sebastian, and it seems that trend is set to continue too. "The Possibilities Are Endless" were the only words Edwyn Collins could say after his debilitating stroke, and are now the title of a new documentary about the man. It was shown before I arrived, and Edwyn and wife, Grace, were here to introduce it. From the new Scottish generation to those who influenced it, the circle is complete.

Some say SXSW is losing its indie credibility and anti-authoritarian standpoint. Once a hippie enclave with a small population, the city's motto is "Keep Austin Weird". But does it still live up to it? For me and countless others, this astonishing set of festivals have not yet lost their edge. There's a reason why musicians, media, tastemakers, movers and shakers flock there every year. It is a phenomenon.

Vic Galloway presents on BBC Radio Scotland at 8.05pm on Mondays (www.bbc.co.uk/radioscotland). Tomorrow synth-pop trio Chvrches perform live session tracks and choose some of their favourites records.Vic's book, Songs In The Key Of Fife, is out now, published by Polygon. Contact Vic at www.twitter.com/vicgalloway