15 things you (probably) didn't know about Guitar Hero

It's made over $2 billion in retail sales, been released on nine formats and clocked up 20 titles - games don't get much bigger than Guitar Hero.

Chances are you've built up a mean set of callouses from your note streak hunting and know the solo to Free Bird better than your phone number - but did you know of the scientific discoveries that have been made thanks to Guitar Hero? Or the incredible records the game has helped set?

Here are 15 pieces of trivia and fact that fans of the series (probably) won't have read before. Rock on.

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(Images: Rex; YouTube; Shutterstock)

1. It helped monitor the UK economy

Such was the prevalence of Guitar Hero in homes of the UK that on March 2010 the Office for National Statistics announced that the game (referred to as 'computer games involving accessories') had made it onto the 'Basket of Goods' - a list of 650 items that are used to help monitor the nation's spending habits and gauge the country's inflation risk.

2. They're controllers, not instruments...

...for legal reasons. In February 2009, a United States District Court settled a dispute that had arisen between Gibson Guitar Corporation and Activision concerning Giboson's 1999 patent for "technology that simulates a concert performance via pre-recorded audio and a musical instrument". The court ruled that the controllers weren't instruments, but rather "toys that represent other items". So no matter how much we might like to consider them real instruments, we're legally obligated not to.

3. One kid set (nearly) all the Guitar Hero records

One boy (now man) remains a legend in the world of Guitar Hero - Danny "Phenom" Johnson. Back in 2009 at New York's Book Expo, 14-year-old Johnson smashed several world records in one sitting. Using Through The Fire And Flames, Johnson managed to obtain the longest note streak ever with 3,722 and the highest score with 985,206. Unfortunately, no one had the foresight to video the momentous occasion - here's a video of him setting his previous record of 973,954 at a Guinness World Record event.

4. You'll never beat this girl

Having previously been hooked on Unreal Tournament, Annie "Ecstacy" Leung transferred her video game obsession to the fretboard of Guitar Hero - with incredible results. Her record-breaking rendition of high-scoring classic Through The Fire and Flamesset a new bar for female gamers, racking up a staggering score of 789,349.

5. Science loves to play too

In 2010, Trent University of Ontario, USA, used Guitar Hero to test the theory of 'sleep learning'. Two groups of students were given the task of learning a Guitar Hero song - one in the evening before they went to bed, another in the morning before a day of regular activities. The study showed that the students' performance of the song was better after a night of sleep than after a similar length of daytime wakefulness.

The game was also used by NASA in a 2013 trial on the effects of microgravity.

6. Guitar Hero III set retail records

Aside from challenging gamers to set world records of their own, Guitar Hero III: Legends of Rock claimed its own world record when it became the first title to make over $1 billion in sales. Upon its launch in October 2007, Activision stated it was the "largest product launch ever", shifting more than 1.4 million copies and making over $100 million in its first week. Within three months, it managed to claim the title of best selling game of 2007.

7. It's been used to help stroke and prosthetic patients

The gentle difficulty curves and rhythmic challenges of the Guitar Hero has seen the series become a tool for various medical practitioners. Physical therapist Elizabeth Penny used a modified guitar controller to help recovering stroke victims regain coordination and physical skills, while engineers adapted the game to allow amputee patients to train with their new prosthetic limbs.

8. It helped Aerosmith make heaps of cash

Aerosmith are big, big Guitar Hero fans. When 2008's Guitar Hero: Aerosmith was released, sales of the game made the iconic American rock group more money than any of their individual albums ever had. As well as raking in money from licensing their songs, Aerosmith also saw a 40 percent increase in catalogue sales the week after the game was released.

9. $25,000

That's how much it costs on average for a games publisher to buy the licence for use of a band's master recording, while permission to record a cover fetches around $10,000. Just remember that next time you're jamming along to your favourite track, and try not to feel any extra pressure.

10. DragonForce can't play their own song

Few guitarists are capable of pulling off the slick riffs and shred licks of DragonForce guitarists Herman Li and Sam Totman. But despite their skills, when the axemen were invited to attempt to play their own epic piece Through the Fire and the Flames, things went horribly, horribly wrong for the pair.

11. Axl Rose isn't a fan of the series

While undoubtedly gaining new fans from the Guitar Hero series, Guns N' Roses front man Axl Rose filed a $20 million lawsuit against Activision in 2010 for what he felt was a misuse of his bands music and the likeness of Slash. Eventually, having had various claims dismissed and elements moved forward several times, a judge dismissed the final case in 2013, believing that the initial claims had been filed too late after the launch of the game.

12. It's injured sports stars

The eagle-eyed fans of the Xbox 360 edition of Guitar Hero II will have seen the message "No pitchers were harmed in the making of this game. Except for one. Joel Zumaya. He had it coming." appear in the credits. This jovial hat-tip was in reference to Detroit Tigers pitcher Joel Zumaya, who managed to injur himself playing the original game during the 2006 American League Championship Series. His game addiction caused him to gain a sore wrist, for which he missed three matches in the World Series playoffs.

13. It had a dig at Axl Rose

For one of the loading screens of Guitar Hero III, the message "Never leave your lead singer in charge of the mix" appears. While this could be a pop at the egos of lead singers, it's more likely a reference to Axl Rose: Amid bad relations with his guitarist Slash, the Guns N' Roses singer replaced a section of Slash's guitar track with the work of Paul Tobias on their cover of The Rolling Stones' Sympathy for the Devil.

14. $1 million

That's all it took to make the original Guitar Hero game. Having enjoyed working on Konami's Guitar Freaks arcade game, RedOctane set out to create a console version of their hardware, partnering with developers Harmonix Music Systems. That $1 million budget was a sound investment, as the group established a video game series that would go on to make $2 billion.

15. Guitar Hero can help improve your guitar playing

While Guitar Hero won't help you pick up the technical sides of guitar playing, the game can teach vital rhythm and timing skills to those uninitiated in guitar playing. Remember that record-breaking teenager Danny Johnson? Johnson was an accomplished musician before he took up the plastic axe, but the insane speeds of Guitar Hero's harder tracks helped turn the record-holder into a skilled shredder. Check out Johnson and his brother's YouTube channel for insight into their impressive skills.