John Frusciante first joined the Red Hot Chili Peppers in the aftermath of tragedy.

As a teen, the would-be beloved guitarist was obsessed with the Chili Peppers, attending multiple gigs and idolizing founding member Hillel Slovak. Slovak recorded two albums with the band before parting ways, ultimately dying of a heroin overdose in 1988 at the age of 26. The rest of the Chili Peppers were devastated, writing songs inspired by him for years to come. There was a bittersweet outcome for Frusciante, however: He would replace his hero. He'd leave the band twice over the course of the following two decades, but last weekend, Frusciante announced that he'd officially rejoined the Red Hot Chili Peppers.

Slovak's death posed an especially trying challenge for the group when it came to making the album that would follow, 1989's Mother's Milk. But it also gave Frusciante an opportunity to start pushing the once cult favorite punks to the massive, inimitable name they've become since the '90s. He's widely regarded as one of the best guitar players of all time, partially responsible for almost all of the Chili Peppers' biggest hits—"Under the Bridge," "Can't Stop," and "Snow (Hey Oh)" among them. The band is undoubtedly at their best with him among their ranks.

To commemorate Frusciante's return, we've rounded up the ten most underrated tracks from the Chili Peppers' discography (that he helped bring to life). Across five records, these songs prove what a crucial talent Frusciante is.

"Higher Ground" (1989)

R.H.C.P - Higher Ground [Official Music Video] (Full HD 1080p Remastered)www.youtube.com

The Chili Peppers' first breakout single was one of the few times in history when a cover eclipsed its original. With this reworking of a Stevie Wonder classic, the band solidified their status as a riveting, funky punk group, with Frusciante's fiery riffs slicing through mercilessly.

"Taste the Pain" (1989)

Taste The Pain (Remastered)www.youtube.com

The first track Frusciante recorded with the Chili Peppers is also probably one of their most eclectic, backing their bombastic rock with a cello feature and eerie, gothic vocals. It was a moderately successful single for the band and an apt introduction to Frusciante; however, the band hasn't performed it live since the Mother's Milk tour.

"Sir Psycho Sexy" (1991)

Sir Psycho Sexywww.youtube.com

Blood Sugar Sex Magik was the album that melded the Chili Peppers' funk-punk origins with more melodic lines; it was also the album that prompted Frusciante's first exit, due to its overwhelming success. The album's ambitious penultimate track—the slow-jammy "Sir Psycho Sexy"—envisioned Kiedis at his most macho and prideful, though Frusciante's guitar licks always worked themselves to the front.

"The Power of Equality" (1991)

The Power of Equalitywww.youtube.com

Though Sex Magik's overarching themes were heavily, well, sexual, opener "The Power of Equality" touched on issues of social justice that most bands of the '80s and '90s—save for the name-dropped Public Enemy—wouldn't dare whisper about.

"Porcelain" (1999)

Porcelainwww.youtube.com

Frusciante's brief replacement, Dave Navarro of Jane's Addiction, only performed on one Chili Peppers record: their commercial dud, 1995's One Hot Minute. He was criticized for his metallic playing style, which overall wasn't conducive to the band's sound. It makes sense that the Chili Peppers would take a softer approach on their follow-up, the highly successful Californication. But hidden behind the mellowed-out smash hits "Scar Tissue," "Otherside," and the title track, there's "Porcelain," a stunningly spare ballad that feels like a breath of fresh air after the band's tumultuous turnover.

"Road Trippin'" (1999)

Red Hot Chili Peppers - Road Trippin' [Official Music Video]www.youtube.com

Life was good during the Californication days. The band was trying to stay sober, and Kiedis, Frusciante, and Flea were closer pals than ever. The album's closing "Road Trippin'" depicts a wholesome cruise down the Pacific Coast Highway with Kiedis and his "two favorite allies": Frusciante and Flea. The track features no drums, allowing the rare occurrence of Frusciante's acoustic fingerpicking to take the lead.

"The Zephyr Song" (2002)

Red Hot Chili Peppers - The Zephyr Song [Official Music Video]www.youtube.com

Upon his first return to the band, Frusciante got big into '80s guitarists and timeless classics like the Beach Boys and the Beatles, taking cues from their prominent melodies when writing By the Way, probably the record he had the most control over out of the band's entire discography. He described the By the Way sessions as one of the happiest times of his life, a bliss that permeates "The Zephyr Song." As breezy as its name implies, the track might be the Chili Peppers' most joyful track to date.

"Minor Thing" (2002)

Minor Thingwww.youtube.com

Frusciante's hand in By the Way was, evidently, a little overbearing, so much so that Kiedis said bassist Flea considered leaving the band. "Minor Thing" is rumored to be about those contentions within the band, even mentioning Mozart—Kiedis' nickname for Frusciante during the era. Nevertheless, the song, like much of the album, is simply beautiful and soars with layered harmonies. Not such a minor thing after all.

"Charlie" (2006)

YouTubewww.youtube.com

Frusciante's time playing with prog rockers the Mars Volta definitely altered his playing style by the time the Chili Peppers released their 2006 double album, Stadium Arcadium. "Charlie"—which boasts a fan-made music video dedicated to Slovak—features a layered guitar track from Frusciante, much more intricate than his usual work with the band.

"Wet Sand" (2006)

Wet Sandwww.youtube.com

"Wet Sand"—which Flea has named as one of his five favorite Chili Peppers songs—was first conceived by Frusciante, who was toying around with different chord progressions for the track. When Kiedis heard Frusciante mumbling a vocal melody, Kiedis picked up on the words "wet sand." He loved those two words so much that he'd go on to use them to construct all the song's lyrics.