Six Nations 2021: England & Wales search for style in silence
In 2018, 50 students in New South Wales took it in turns to climb into a driving simulator.
While they dodged pedestrians and weaved through traffic, two speakers sat either side of them. Sometimes they played Metallica. Sometimes Motley Crue. Sometimes nothing at all.
All the while, computers assessed how their driving changed.
The results were clear. Those listening to music broke the speed limit more and for longer than those driving in silence.
On Saturday, when England pitch up at the Principality Stadium, the usual soundtrack of aggro and pyro will be muted.
There will be no bus-butting as they inch through crowded Cardiff streets. No Tom Jones sing-along as they warm up. No roar of expectation as the first kick sails up towards the rafters.
But if the 80 minutes that follows is different, the lack of a backing track may not be why.
Usually Wales v England is, to rework the French, hostility, physicality, intensity. Two juggernauts set on a collision course. A destruction derby of a Test match.
This year demands something a little smarter, a little stealthier.
"My concern is England throw the kitchen sink at Wales," said former England scrum-half Matt Dawson on BBC Radio 5 Live. "That they try to pummel Wales."
"Wales can then show a little bit of brain. Alun Wyn Jones and his senior players can slightly outfox England.
"England don't need to up their physicality, it's the top two inches."
Nowhere is the change of tack clearer than in midfield.
Last year in England's win at Twickenham, Manu Tuilagi, out at 13, carried the ball more than any other England back. In fact only one forward, Tom Curry, bettered his total.
Five years before it was the same stage, a similar story, if a different outcome. Jamie Roberts and Sam Burgess left craters around the gainline and England's World Cup hopes finished in tatters.
These two line-ups ask different questions.
In Owen Farrell and Henry Slade, England have a distribution network to rival Amazon. Whether spreading wide or kicking long they can deliver the ball to all areas of the pitch.
The punch and penetration others offer is lost in the post, however.
Wales have an intriguing combination.
Jonathan Davies, normally afforded time and space to coordinate defence and sniff out space at 13, is closer to the fray at inside centre.
Wing George North, winning his 100th Wales cap but making only his eighth start in midfield, is at outside centre.
Both, at their best, are sublime players. But the chemistry between them is uncertain, tested only once in a Autumn Nations Cup win over Italy.
There will be no falling back on well-oiled patterns. No autopilot option for a phase or two. In an area where Wales have previously been drilled as tight as a marching band, the two centres will have to riff off each other.
Given Tuilagi's injury run, England have had plenty of time to work out alternative attacking rhythms. And, most often, they have used boot rather than ball in hand.
It has been effective. England scored four of their six tries in a 44-8 win over France in 2019 after finding acres of backfield space. Accurate box kicks with a furious chase were key to their run to the Rugby World Cup final six months later.
On the opening day of this season's competition, however, Scotland and Stuart Hogg were ready and waiting. They covered the space, returned fire and won the day.
Rather than tried and tested, England's percentage game was tired and bested.
For this week, those tactics, if not torn up, have been tweaked.
Replacement scrum-half Dan Robson spoke on this week's Rugby Union Weekly of "putting the ball up on these young wingers and really going after them".
Coach Eddie Jones, meanwhile, publicly mulled over 20-year-old Louis Rees-Zammit's "deficiencies" and the inside line that Gloucester team-mate Jonny May could provide on the young star's game.
Mathew Tait, who walked into the Millennium Stadium in 2005 as a teenage wonderkid and was almost carried out of it by Gavin Henson, can attest to how this fixture can trash growing reputations.
But, with Liam Williams at full-back, Rees-Zammit has the ideal wingman for the incoming barrage.
Amid those skirmishes, some big answers may emerge.
England won two trophies in 2020, but without really convincing.
Wales have won two out of two matches in 2021, but by narrow margins and with superior numbers.
Both seem to be in search of an identity, even if they have not been short of results.
Nearing the halfway point of a World Cup cycle, and the back end of a pandemic, both Jones and Wales counterpart Wayne Pivac hope the masks come off soon.
That their sides' real self stands up and stands out amid the silence.