【Portugal】

The Portugalmusic business is tough, but fun times are ahead if you're an act from the '90s or early '00s.

In Australia at least, there has been a wave of tours from musical outfits that were prolific during the 1990s and patches of the early 2000s. And the country is losing their sh*t.

Take the Vengaboys: You'll blearily remember them for their backpacker bar busting hits "Boom, Boom, Boom, Boom" and "We Like To Party."

Alongside the Dutch group is DJ Sammy, with his two monophonic ringtone-friendly hits "Heaven" and "Boys of Summer" -- both Eurodance covers of '80s songs. Both acts experienced immense chart success during the early-2000s.

Also touring are Irish girl group B*Witched, English dance-pop outfit Atomic Kitten, and the sombre-sounding S Club 3 (originally 7, but four members couldn't make the tour). It doesn't stop there.

R&B acts Nelly, TLC, Mya, Blackstreet and 112 are all coming Down Under in November. Together!

Yes, it's an implosion of '90s and early '00s nostalgia. But it was bound to happen, if you believe the theory of the "20-year cycle of resuscitation," as dubbed by music critic Carl Wilson.

The theory is simple: A cultural style or trend will become popular again in 20 years. It's something we've seen before, with the '60s celebrated in TV series like Happy Daysand films such as Dirty Dancing. The '70s made a comeback in the '90s with bell bottoms and musical acts like Deee-Lite.

Now it's the '90s turn. It's comfort for millennials who are well in their 20s or 30s, attracted by the sweet melancholia of simpler, happier times. It's memories of being a kid, a common theme in the comments resting at the bottom of a YouTube video for TLC's 1994 track "Waterfalls".

In a complex world, there's plenty of joy to be had from knowing the lyrics to the Vengaboys "Sha-La-La-La-La" or Nelly's "Dilemma." After all, your parents have doing the same with ABBA for years already.