Sampling is the act of reusing elements from one recording in another, and it's a process that has taken over popular music. Hip hop was the first genre of music to use sampling as a major building block, as early as Sugarhill Gang's classic "Rapper's Delight" sampling Chic's classic "Good Times."

More recently, though, sampling can become one of the reasons why some songs get as big as they do, due to familiarity. For example, Kanye West's "Stronger" and its sample of Daft Punk's "Harder Better Faster "Harder Better Faster Stronger," and in pop music with Pitbull and Christina Aguilera's "Feel This Moment" with its sample of a-ha's oh-so '80s hit "Take On Me".

Songs with samples are always fun because of their nostalgia factor, but the idea in underground hip hop is to search for the most archaic, obscure, how-did-you-even-find-that sample and turn it into a song for today. You could even take a song people would normally recognize and somehow make something entirely new and unrecognizable out of it. Songs with samples like these can become underground hits, but some lucky tracks can reach the national level, with the public not realizing that a sample is even being used.

Here are some examples:

1. Drake's Hotline Bling samples a record from 1972

To begin, we have an example of a sample secretly constructing an entire beat. "Hotline Bling" takes from Timmy Thomas's "Why Can't We Live Together," a simple soulful record from the '70s that only features a subtle percussion loop, an organ and Thomas's voice. On a related note, Drake's hit was also originally credited as a remix to rapper/singer D.R.A.M.'s underground smash from last year "Cha Cha", a song definitely worth checking out.

2. Flo Rida's G.D.F.R. samples the theme song to George Lopez

If you were wondering who this Lookas person also featured on the track is, he's a producer and the instrumental to Flo Rida's "GDFR" was based off of his trap remix to War's "Low Rider," which some of you may associate with George Lopez's TV family jumping around in slow motion. Funny enough, the horn lick that became GDFR's chorus is found only at the very end of "Low Rider" as the track is fading out (see around 2:55 in the video below).

3. Lil Wayne's 6 Foot 7 Foot samples that one song from Beetlejuice

Lil Wayne and Cory Gunz's 2011 track features a sample of the vocals from Harry Belafonte's 1956 rendition of the Jamaican folk song "Day-O (The Banana Boat Song)," featured in, among other thigs, a surreal scene from the 1988 film Beetlejuice. The section looped as soon as the drums kick in on the Wayne track can be heard around 38 seconds into the video below, while the main "six foot, seven foot, eight-foot bunch" sample can be heard at 1:01.

4. Gotye's Somebody That I Used To Know samples a 1967 track by a Brazilian composer

Gotye may have only used the first second and a half of Luiz Bonfá's "Seville," but it definitely went a long way. "Somebody That I Used To Know" topped the charts in over 20 countries and became Gotye's signature song, inspiring countless covers including a viral one by the band Walk Off The Earth in which all five band members share a single guitar.

5. Passion Pit's Sleepyhead samples a traditional Irish folk song

Indie electronica collective Passion Pit burst onto the scene in 2008 with their debut single "Sleepyhead" from their first EP Chunk of Change. Along with a quick sample from a poem by Jack Kerouac, which you can spot in the song three seconds in, "Sleepyhead" samples a recording from Irish singer and harpist Mary O'Hara of the folk song "Óró Mo Bháidín," Gaelic for "Oh, my little boat," which you can find 19 seconds into the video below.

6. Gnarls Barkley's Crazy samples the soundtrack to an Italian spaghetti western

Singer-songwriter CeeLo Green and producer Danger Mouse are Gnarls Barkley and their debut single "Crazy" released in 2006 was unlike anything on the radio at the time, surely in part due to its sample of a track titled "Nel Cimitero Di Tucson" composed by brothers Gianfranco & Gian Piero Reverberi for a 1968 film originally titled Preparati La Bara, released in the US as Django, Prepare A Coffin.

7. Britney Spears's Toxic samples an '80s Bollywood film

Truthfully, this song and its sample inspired this article. Britney Spears's 2004 song "Toxic" reached number one in six countries and the top five in nine others. The song's unique sound is created with the help of the song "Tere Mere Beech Mein" composed by Lata Mangeshkar and S. P. Balasubrahmanyam for the 1981 Bollywood film Ek Duuje Ke Liye. The sample used in the intro can be heard 25 seconds into the video below, with the high pitched melody six seconds in.

BONUS: Skrillex's Scary Monsters and Nice Sprites samples the celebration of a speed stacker

Short, sweet and silly samples are staples of dubstep tracks, especially in Skrillex's earlier songs. I leave you with the source of the famous vocal sample featured before the drops in "Scary Monsters and Nice Sprites," seven seconds in for the impatient.