Last year, we were collectively inspired by Pixar's Up, a movie about fulfilling lifelong travel dreams with the help of several thousand helium balloons. If you're looking for a simpler way to get your airborne on, try putting on Led Zeppelin's Stairway to Heaven, Tom Petty's Free Fallin', or Radiohead's Subterranean Homesick Alien. You might be surprised to see just how directly the music affects your sense of elevation.

The famous fingerpicked intro to Stairway to Heaven sounds suspiciously like the intro to "Taurus," a song written 3 years earlier – by a band Zeppelin used to open for. Regardless of its origin, however, the rise and fall of the intro perfectly anticipate not only the overall structure of the song, but also the rising and falling of the opening lyrics.

This has the effect of accentuating certain words while forcing others out of the spotlight. If you wanted to represent ascending and descending lyrics visually, you might try something like: "there's A LAY-DEE Who's Sure / all That GLIT-TERS IS Gold." Since "lady" and "glitters" are emphasized at the expensive of "sure" and "gold," we get an almost subliminal message not to be too sure about that whole gold thing.

The same thing happens with Robert Plant's final, plaintive cry: "And SHE'S BUYYY-ING The Stair-way to HEAV-en." In this case, "buying" is king of the hill, "stairway" then descends dramatically - something atypical of ones that lead to heaven, and "heaven" takes a big dip in the second syllable. You'd expect heaven to have a little more lasting power than that.

Coupled with the overall crescendo/descent motif, the fact that the lady's "heaven" and "gold" aren't what they're cracked up to be has lead a lot of people to believe that Stairway to Heaven is about taking - or possibly overdosing on - drugs. And considering that there's a "piper" running around in a forest filled with "rings of smoke," echoes of "laughter," and "humming" heads, it really does make you wonder about the meaning of Stairway to Heaven.

Like in Stairway to Heaven, the opening notes of Tom Petty's Free Fallin set the tone for the rest of the song. The first five seconds introduce a musical arc that repeats throughout the stanzas – and explodes in the chorus. Thematically speaking, this arc often gives the lyrics an ironic twist. Take, for example, the second line of the second stanza. It starts, "there's A FREE-way," and immediately, we're thinking open spaces and wind in the hair. We then hear, "running through the Yard," which brings us down a notch through both the literal meaning and the overall drop of the notes.

The chorus has the same auditory effect: starting with, "yeah I'm FREEEE," it makes us want to throw out our arms and let out a barbaric yawp - or turn the stereo up in traffic, as the case may be. Next there's a pause, which is the musical equivalent of the moment where Wile E. Coyote realizes he's hanging in midair. Finally, Tom Petty adds, "FREE FALL-in'," which brings us back to earth.

Not to completely ground the mood, however, the chorus is echoed by the backup singers, the recurring arc of guitar notes, and actual, literal echoes. This gives the song a huge sense of open space that keeps us from getting too bummed about that whole "falling" thing. (Plus, if you want to "write her name in the sky," you'd better have some sky to do it in.) What we end up with is a series of contradictions that weirdly – but effectively – dignifies the idea of having no safety net in life. No wonder the song's so universally loved by college students.

True to style, Radiohead's Subterranean Homesick Alien has a slightly more complex musical dynamic going on. The opening ten seconds of the song feature guitar notes that fall in stages - much like a "beautiful" alien spacecraft might approach the earth's surface. Inorganic sounds of the electric keyboard then take over, swooping and soaring to set the mood for some intergalactic space travel.

The lyrics contrast the depressing monotony of life on Earth with the elevated perspective that an alien race would have on the universe. Thom Yorke sings, "up a-BOVE / aliens HOV-er," and every time a note hops at the end of a line, we can almost hear his desire to join them. However, the chorus is subtle message of defeat: humans are too "UP-TIGHT, Up-tight" to understand, and as hope diminishes, so does the pitch of Yorke's voice.

These shifting moods capture the struggle between what's earthbound and that's celestial - or perhaps they simply express the anxiety of someone who fears "they'll put [him] away." The final fifteen seconds of the song repeat the opening ten, but with a twist: now, instead of simply the descending guitar notes, there's the simultaneous rise of the electric keyboard, which sounds an awful lot like something flying away. In a sense, the end is a parting between the daydream and the reality. Whether or not this is a bad thing probably depends on your opinion of the narrator's mental health.