Now that things have wrapped up in WGI color guard competition, the focus has turned to the percussion groups, who are set to take over Ohio and Northern Kentucky from April 21-23.

WGI Percussion World Championships are a full two weeks after their guard counterparts, though, so there's so much room for change and movement between the end of March - the end of Regional season - and late April.

But as we impatiently await the full weekend of Percussion action, here are five key competitive storylines to chew on:

1. Checking In On the Champions

Since it's been three full years since the last edition of the WGI World Championships, it seems like as good a time as any to do a little bit of a recap of what happened in 2019. 

Here's a brief primer on what reigning champions have the best chance to defend their titles in 2022:

• Independent World - Broken City: This article will unpack Broken City's chances of a second gold medal further, but generally speaking, the chances aren't bad at all. Broken City enters April less than two tenths behind one of its closest California running mates, Pulse Percussion.
• Scholastic World - Chino Hills HS: Again, we'll get into this further - but Chino Hills has shown no signs of slowing down on its road to a fourth straight title. The SoCal group won its last two WGI appearances by right around two points, against deep California PSW lineups. 
• Independent Open - Bakersfield College: Bakersfield will certainly be in the running to defend its title, but recent events have proven it's got competition. We'll get further into the PIO race a little later, but it might be the most wide-open class in percussion. 
• Scholastic Open - Sparkman HS: After a rail-thin victory in 2019, Sparkman made the move to World Class for 2022. That being said, three of the other top-five groups - Clear Brook (2nd), Norwalk (3rd), and Fair Lawn (4th) will all have their hat in the ring, and both Clear Brook and Norwalk enter April with WGI Regional victories already under their belts this season. 
• Independent A - Unity Percussion: Unity Percussion isn't among the 17 groups competing in this year's PIA division, so it's anyone's ballgame to earn a gold medal in 2022. 
• Scholastic A - Grand Blanc HS: On one hand, the PSA division hasn't had a repeat champion since its first two years of existence in 1995 and 1996. But in the defense of Grand Blanc - which is back for 2022 amongst a field of 47 A Class groups - the Michigan ensemble did pick up a win at its only WGI Regional appearance, back in mid-February.

2. PIO Carousel

Here's an absolutely insane fact about Percussion Independent Open - in 23 different seasons of PIO competition, there have been 23 unique PIO gold medalists.

So, history would lead one to believe that someone will get their first-ever PIO title in 2022.

As was mentioned before, 2019's champion is no slough. That year's runner-up, too, is more than capable of earning what would be its second-ever PIO championships - that's Matrix Open, which won in 2018 and finished in second in 2019. Mathematically speaking, with a couple of Regional wins under its belt, it might be fair to call Matrix Open the frontrunner. 

But again, no one's ever won a PIO title more than once. So, allow me to throw a couple of other names into the ring.

For starters, how about Cap City 2? This is their first year competing in PIO championships, and they just scored within five hundredths - that's 0.050 - of Matrix Open on March 27th. That's basically a tie. 

Of the rest of 2019's top six, though, three more groups will be in attendance and they're all seeking first-ever PIO titles too - Infinity 2, Liberty University, and Triple Crown. 

Of all the PIO groups mentioned here, Infinity 2 and Matrix Open are the only ones with WGI Regional wins this year, but of course, Cap City 2 was right in the running for one just a few weekends ago. 

Freedom Percussion is also worth keeping an eye on - they didn't compete among 2019's PIO groups, but won a head-to-head early-season battle over the aforementioned Cap City 2. 

Anyway, in conclusion, if you're into scores and competitive intrigue, PIO is going to be bonkers fun.

3. New PIW Champion?

After several years of top-five finishes, Broken City finally broke through in 2019 and earned its first Percussion Independent World win - with an all-time PIW high score to boot. At the top of 2019's PIW standings, Broken City separated itself from silver-medalist Pulse Percussion by more than a full point.

It's been three years, but it appears Pulse may have its chance to flip that script. 

At the WGI San Bernardino Percussion Regional, Pulse Percussion finished atop two nights' worth of a nine-deep PIW lineup. Broken City sat in second place both nights, by paper-thin deficits of 0.20 and 0.15.

Anything can happen, but it appears, based on March's competitive results, we're in for a thrilling race between this pair of California World Class groups.

4. But Wait, There's More 

It's labeled as "4," but this one's more like "3A." And that's because, of course, Pulse and Broken City aren't alone.

Now, it's hard to compare scores from one end of the country to the other. So, take those raw final scores with a grain of salt. But there's another tight PIW race brewing in the Midwest. 

Rhythm X and Music City Mystique are always a pair worth following competitively throughout the WGI season, largely due to their close competitive and geographic proximity. Earlier this year, Rhythm X opened up an advantage of 2.15 points over Mystique. That lead, following the recent WGI Dayton Percussion Regional - while still in Rhythm X's hands - is down to 0.75.

On one hand, sure, mathematically, trends would say MCM is headed in the right direction. On another, those numbers are just two samples. While it's much closer than two-plus points, 0.75 isn't a tiny gap. 

Either way, anything within a point always feels up for grabs, so with two pairs of PIW groups entering April separated by less than 1.0, the stories write themselves. 

5. PSW Four-peat?

Chino Hills has been the reigning Percussion Scholastic World winner since 2017. Of course, due to there being no full, in-person WGI season in either 2020 or 2021, that means they've won just three gold medals in a row. 

Just three in a row, though? Yeah, no big deal.

So, the question remains - will the streak bridge the gap from 2019 to 2022? 

No Scholastic World group has ever won four titles in a row - let alone three, actually. The last PIW group to win three in a row was Music City Mystique from 1996 - 1998. And the last group of any classification to win four titles in a row was Scholastic Open's Pacifica High School in the mid-2000s. 

Chino Hills will have its fair share of suitors for the ultimate prize. After defeating the Scholastic World field in San Bernardino by two points, though, it appears Chino Hills is at least in a position to create some more history in Dayton this year.