Pentatonix is an a cappella group comprised of five members. (Penta! Ay, get it?) Back in 2011, they won Season 3 of NBC's "The Sing Off," a strictly a cappella competition show. The group has since acquired international fame and numerous prestigious musical awards and accomplishments. While these honors speak to their talent as a musical force to be reckoned with, what renders PTX — as their fans often call them — unique are the genuine dynamics of the group coupled with the honest passion and creative individual energy each of them brings to the table.

Let's meet the group members, shall we?

Scott Hoying is for all intents and purposes the group's leader. He is the baritone voice and does the majority of lead vocals for the songs. His riffs are unbearably sweet. He bids you welcome.

Mitch Grassi is the powerhouse who hits those incredibly smooth and disciplined high notes as the group's tenor.

Kirstie Maldonado is the fabulous and solitary lady of the group. Her mezzo-soprano capabilities ring out beautifully in any arrangement. Note the sly side-smile she often dons as she sings.

Avi Kaplan functions as the group's bass with his unreal range. His voice can go so low that when he addresses the audience at live concerts it's often difficult to understand what he's saying.

Kevin Olusola serves as the group's beatboxer. He and Avi were termed the Meat and Potatoes of the group by the judges of "The Sing Off" because of the underlying depth they provide. Without them, PTX's songs would sound quite hollow. They are the ones who create those underlying beats that give Pentatonix the original sound that catapulted the group into contention with popular artists. Kevin also plays the cello (because he's a boss) and is credited with developing the art of "celloboxing."

Now that we know who's who, let's get into the reasons why you should follow them as obsessively as I do.

1. The technicality of their work.

They do it all with their mouths. Seriously, just take a second to think about how incredible that is. The five of them are highly trained, but it takes such a raw talent to have an ear and a vocal capability to hit the very specific notes that they do, all while hearing their group-mates making very different sounds.

If and when the impending zombie apocalypse happens, the a cappella music of Pentatonix will carry us through on a comforting wave of mellifluous melody, keeping us entertained and creatively sustained with no equipment required.

2. They keep it fresh.

Pentatonix began their YouTube career by posting their arrangements of covers of current songs as well as old classics. Their cover of A Great Big World's "Say Something" was released in February 2014, right as the song was gaining popularity.

With instances such as Avi's live rendition of Misty Mountains from the film "The Hobbit", Pentatonix speak not only to the theater nerds, but to those who love works of fantasy as well.

They also intermingle fandoms by being a part of such events as this phenomenal teaser of 2015's "Star Wars: The Force Awakens" at the American Music Awards.

As the group began to tour, the process of simultaneously producing new albums and performing past ones became routine. They would perform an entire set at night and, in their free-time, hop into the recording studios to perfect the tracks of their upcoming album. Talk about multi-tasking! Since "PTX Volume I," the group has increased the number of original titles with each new album, building up to the fully original 2015 self-titled album, "Pentatonix."

3. They genuinely appreciate their fans.

Here is where I delve into the personal anecdotes.

Summer 2012

My mom and I were lucky enough to meet Pentatonix in the summer of 2012, a year after they had won "The Sing Off," but before they had made any major record deals. This was a free, open-to-the-public concert at City Walk of Universal Studios Hollywood. After their beautifully arranged, albeit semi-unorganized set, the stage manager announced that the group would love to meet everyone, but they may not have enough time. My mom and I wiggled our way up to the front and were the first to meet the five of them. They were so incredibly gracious. We got to hug each of them and share a hurried 15-second conversation. I achieved my fangirl goal when I told Mitch that his voice makes me melt.

That's me in between Avi and Kirstie and my mom in between Kirstie Maldonado and Scott Hoying. I regrettably do not know the name of the girl on the end next to Kevin Olusola — she was a fellow diehard fan, so I'm glad to share her presence in this format!

Spring 2013

My friend and I ran into Scott as he was disembarking the tour bus hours before the concert in Boston. He was gracious enough to snap a picture with us, even with his coffee and travel bag in tow!

Fall 2014

Avi favorited the tweet in which I praised his honey-sweet lead vocals in the song "Standing By" from the PTX, Vol III album.

But enough about me. On the larger scale, the Pentatonix give back to their fans in their genial interactions with every single one of them. From the stage at live concerts, they continuously share their appreciation to the audience for their support.

On the group's first tour, Kevin and Avi would interact with the crowd in-between sets with amiable, witty banter. Continuing through their most recent tour in 2015, each member of the group will teach the audience their own voice parts for segments of particular songs. They, in effect, offer a singing lesson for those of us who so highly admire what these five are capable of and give the audience a shared experience of (hopefully) accurately hitting the notes of the songs we so love. Pentatonix takes the time to engage with their spectators in a way that performers often do not even consider.

The group also invites their fans to join them in the celebration that is singing on their actual album. For the high-energy song appropriately entitled "Sing" from their most recent album, the accompanying music video consists of the segments of Pentatonix filming themselves with a camera-phone as they gallivant around town. These moments are interspersed with video clips sent in by fans singing along. The video culminates in the group members meeting up with droves of their fans on an idealistic party spot: a pier in California. If this song and video don't make your day, I don't know what will.

4. Scott and Mitch's Youtube Channel.

SUPERFRUIT provides your weekly dose of hilariously sassy, carefree vibes. Scott and Mitch post videos every Tuesday in which they offer life advice, answer fans questions and play ridiculous games often featuring other YouTube stars. In almost every episode — unless it's a music special — the two each share their personal weekly obsessions and their song of the week.

This episode was posted two years ago and is still a favorite of mine. If I'm being honest, I saw this before I even saw "Frozen."

5. They raise the bar for the music industry.

By returning to an older style of song and performance that does not require instruments, Pentatonix revolutionized the way the world views, or rather listens to, a cappella music. They have helped catapult a cappella into the popular sphere (along with "Pitch Perfect," of course, in the sequel of which they make an appearance).

The summation of the group member's youth, their adaptability and their range of genre that defies being labeled as a singular interest group guarantees a long, fruitful career ahead of them. Hop on the penta van wagon now so you don't miss one beautiful moment of it!