Beginning to play guitar is like fishing in the ocean for the first time. Where does one cast a line?

The answer has changed over the decades, but there are some songs that remain eternal starting points — the base camps at the Mt. Everest of learning the instrument, to cavalierly toss a second metaphor into what’s almost always initially a sonic fray.

So, to put this musical starting line (metaphor three!) in perspective, here’s a rundown of 10 of the most common gateway songs to guitar mania:

• “Sweet Child O’ Mine”: No instrument shop was safe for at least two years after this song became a single in August 1987. Blame Slash. His insanely catchy string skipping Gibson Les Paul riff on the intro to Guns N’ Roses third radio hit was imitated by every kid shopping for a first guitar. As legend goes, Slash first played the part during a rehearsal as a joke, but the joke was on every hapless music store employee or patron within earshot.

• “Eruption”: And before “Sweet Child O’ Mine” ersatz versions of Eddie Van Halen’s “Eruption” solo spewed equally deadly fumes, making Eddie the first guitarist revolutionary to also impair the instrument. Imagine six ambitious young would-be players trying to hammer their way into fame at the same time… in different keys… and the horror of what once was typical guitar store static becomes chilling palpable once again.

• “Wild Thing”: For a generation of players who came of age after 1966, this was common ground – the first chapter in the bible of three-chord rock. Originally a hit for first-generation psychedelic rockers the Troggs, it’s been unoriginally played by everyone including Hendrix ever since.

Troggs Wild Thing

• “Knockin’ on Heaven’s Door”: For every struggling guitar player who can’t quite get it down, this beautiful Dylan classic is also the perfect tune for setting up the line, “I’m not really interested in guitar playing. I only want to learn guitar as a tool for songwriting.” Excuses aside, this four-chord wonder does have its charm and, since it incorporates a seventh chord, does push the envelope for beginners harder than “Wild Thing.”

• “Rockin’ in the Free World”: Okay, Neil Young’s performance of this number has more meat than its circular Em-D-C-G method. First of all, it’s a protest number from 1989 — a time, like now, when we really needed protest numbers. And Young’s solos rip. The real lesson here for budding players isn’t that it’s an easy song to play with just a handful of chords, but that a handful of chords can be used to travel to remarkable places. It’s a great springboard for ideas and improvisation.

• “Smoke On the Water”: Along with “Cat Scratch Fever,” the two-string intro to this number might be the most copped melody of the classic rock era. But does anybody besides Deep Purple actually know the rest of the song?

Deep Purple Smoke on the Water

• “Iron Man”: Another two-string wonder, and a great tune, but if suddenly all the distortion pedals decided to leave the Earth in protest over decades of abuse, would any beginner ever start here again? You bet!

• “Seven Nation Army”: Alternating between three- and two-chord riffs in E, this modern classic by the White Stripes is a perfect example of Jack White’s ability to build great mountains out of sonic molehills. It’s the same kind of estimable talent that made John Lee Hooker such a great player. You schooled players who scoff, trying playing Johnny Lee’s stuff the way he did it and I guarantee all your learnin’ will not help your sorry hind quarters play “Boogie Chillen” correctly. Anyway, a song like “Seven Nation Army, “ which let’s a beginner stay in one easy-to-navigate stream yet requires quick, decisive changes, is a good place for anyone to commence.

• “Working Class Hero”: With one chord less than “Knockin’ On Heaven’s Door,” this John Lennon classic is also a crutch for budding “songwriters,” but only if it’s allowed to play out that way. Unlike Dylan, Lennon throws in an E hammer-on and an open A string, thus giving “Working Class Hero” the higher purpose of illustrating how a held chord can be a living, changing thing instead of a stagnant strum-ble bum.

John Lennon Working Class Hero

• “No Rain”: This is ground zero for a generation of jam band players, which, needless to say, makes it a mixed blessing. Some mistake it for a kind of Americana touchstone, but with its E-D-G-A structure, it’s pretty much a slacker “Wild Thing” in a frou-frou bee costume. Not that there’s anything wrong with that.