# Who’s Hot, Who’s Not? Using Algebra To Analyze Viral Phenomena

Usually, by the time your grandmother starts doing the “Dougie”, you know things have gotten out of hand. Since YouTube’s launch a decade ago, it has made it all too easy to reach millions of people with a catchy video and become a viral sensation. Many videos become “viral” overnight, but few stand the test of time. Some grow organically, others are the clever, contrived work of advertising agencies and production companies. I’m always amazed by the “started from the bottom” dance crazes, where a music video that cost nothing to make becomes a global banger. Not counting cat videos, or Bat Dad (my favorite), who makes your list for the top viral videos of all time. Furthermore, who’s got the hottest dance right now flooding the interwebs? Join the discussion below…

# Mashup Math: Learn How to Become a Remix DJ Using Algebra

Turn on the radio or surf YouTube for music, and you’re bound to run into a remix of a song you already know. Remixes of songs can change the music or beat or insert new verses by rappers (often to try to get a song more airplay — Nicki Minaj doesn’t get a quarter million for a verse for no reason!). Sometimes a DJ might combine two different songs to make a new work, sometimes called a “mash-up.” DJs like Girl Talk or DJ Earworm have become popular taking anywhere between two and twenty-five different songs and mashing them together into new ones.

## The secret behind beat-matching is knowing the math.

What you might not know, though, is that remixing is a process that requires careful mathematical calculations. Every song has its own tempo, or speed, and usually songs that might sound like they share a tempo are still slightly different.  Beats per minute or BPM tells us  exactly how fast or slow a song is. If you try to put an element of one song on top of an element of another one — mixing and matching beats, rap verses, or melodies — you’ll find that songs with different BPMs won’t match, and what you’ll hear is a total mess.

Although some software will automatically “beat match” different songs, slowing down or speeding up two songs so that they have the same BPM, the secret behind beat-matching is knowing the math. What computer programs now do automatically, DJs once had to do themselves, slowing down or speeding up one song to match the tempo of another. By understanding how this math works, you’ll be one step closer to really knowing how popular remixes really work. What songs would sound better faster or slower? How much would you need to speed them up or slow them down to get the effect you’re looking for? These creative decisions would be impossible without the mathematical knowledge to back it up.

# Who’s Hot, Who’s Not? Using Algebra To Analyze Viral Phenomena

Usually, by the time your grandmother starts doing the “Dougie”, you know things have gotten out of hand. Since YouTube’s launch a decade ago, it has made it all too easy to reach millions of people with a catchy video and become a viral sensation. Many videos become “viral” overnight, but few stand the test of time. Some grow organically, others are the clever, contrived work of advertising agencies and production companies. I’m always amazed by the “started from the bottom” dance crazes, where a music video that cost nothing to make becomes a global banger. Not counting cat videos, or Bat Dad (my favorite), who makes your list for the top viral videos of all time. Furthermore, who’s got the hottest dance right now flooding the interwebs? Join the discussion below…

# What are your odds of surviving a zombie apocalypse?

In the cliffhanger Season 6 finale of the Walking Dead, the group once again got themselves into a terrible situation that is definitely going to end with one of them dying. And this won’t be the last time. It seems like Rick can’t get it together. This got us wondering, “Could we do better?”

We built mathematical projections for zombie survival strategies and ran the numbers, and came up with the quiz below. Check it out and see how your personal zombie survival plan will work out.

Turns out that no, none of us would do better than Rick. By our count, of people who followed Rick’s lead, about 4% are still alive. 4% is almost double the maximum survival project in our model (1.9%).  Rick defied not just the odds, but also the basic realities of the U.S. food and ammo supplies and the extreme difficulty of just walking down a city street. He might have seemed like an idiot in Season 1 (and also Season 2, and arguably about half the episodes in Season 3), but you can’t argue with results.

In the lesson below, students will  learn how we arrived at our quiz’s model, and make a model of their own to predict additional zombie survival strategies.

# Mashup Math: Learn How to Become a Remix DJ Using Algebra

Turn on the radio or surf YouTube for music, and you’re bound to run into a remix of a song you already know. Remixes of songs can change the music or beat or insert new verses by rappers (often to try to get a song more airplay — Nicki Minaj doesn’t get a quarter million for a verse for no reason!). Sometimes a DJ might combine two different songs to make a new work, sometimes called a “mash-up.” DJs like Girl Talk or DJ Earworm have become popular taking anywhere between two and twenty-five different songs and mashing them together into new ones.

## The secret behind beat-matching is knowing the math.

What you might not know, though, is that remixing is a process that requires careful mathematical calculations. Every song has its own tempo, or speed, and usually songs that might sound like they share a tempo are still slightly different.  Beats per minute or BPM tells us  exactly how fast or slow a song is. If you try to put an element of one song on top of an element of another one — mixing and matching beats, rap verses, or melodies — you’ll find that songs with different BPMs won’t match, and what you’ll hear is a total mess.

Although some software will automatically “beat match” different songs, slowing down or speeding up two songs so that they have the same BPM, the secret behind beat-matching is knowing the math. What computer programs now do automatically, DJs once had to do themselves, slowing down or speeding up one song to match the tempo of another. By understanding how this math works, you’ll be one step closer to really knowing how popular remixes really work. What songs would sound better faster or slower? How much would you need to speed them up or slow them down to get the effect you’re looking for? These creative decisions would be impossible without the mathematical knowledge to back it up.