★★★★☆

Even after 20 years of making music, Coldplay has remained astonishingly relevant. As other long-standing bands have faded out and new sensations have flashed and disappeared, the British four-piece has managed to maintain its status as a household name in alternative rock because of its readiness to experiment with new musical styles.

The band’s latest album, “A Head Full of Dreams,” which was released Dec. 4, is a further demonstration of its adaptability, this time to a more pop-music sound. The album is a

“poptimistic” rebound from “Ghost Stories,” the band’s gloomy 2014 record written in the aftermath of frontman Chris Martin’s breakup with Gwyneth Paltrow, who even offers vocals on one of the new tracks, “Everglow.”

Starting from the first song onward, the album has a noticeably upbeat tone. “A Head Full of Dreams” sets the mood with funky guitar and bass riffs. The album’s two singles are also particularly cheery, with a funky melody fit for a dance party in “Adventure of a Lifetime” and quick drums and a bright piano on “Birds.”

Two of the album’s most memorable tracks are “Kaleidoscope” and “Everglow,” both of which deviate from the pop-song formula. “Kaleidoscope” is a partial reading of a poem written by Persian poet Rumi accompanied by ambient piano music. Woven into the outro of this two-minute song are snippets of Barack Obama singing “Amazing Grace” at the funeral of Sen. Clementa Pinckney, who died in the Charleston church massacre. The song is a very spiritual break in an album that Martin professed would be something to “shuffle your feet to” in an interview with BBC.

Likewise, in the midst of the synthesizers, “Everglow” calls back to the band’s roots and what they have always done well: an emotional piano ballad a la “The Scientist” and “Proof.” “Everglow” is the open, emotional core of the album that pulls on your heartstrings in that special way only Coldplay tunes can.

However, it is disappointing that the album’s weaker points are found in its collaborations with renowned artists. In “Fun,” which features Swedish pop singer Tove Lo of “Habits” and “Talking Body” fame, the high harmonies lack Lo’s distinct sound and could be mistaken for just any background singer. That being said, “Fun” is one of the more lyrically developed songs on the album, marking Chris Martin’s post-breakup acceptance and contributing a solid sonic landscape to the middle of the album.

“Hymn for the Weekend,” which features none other than Beyoncé on vocals, also makes it seem as though Coldplay is trying a bit too hard to climb on the party-pop bandwagon. The chorus, which repeats the verse “I’m feeling drunk and high, so high, so high,” multiple times, falls very flat.

Bizarre lyrics are once again at fault with “Army of One” and the hidden track “X Marks the Spot.” “Army of One” fits with the album’s overall positive sentiment, but its metaphors — “My heart is my gun” — seem a little unusual. “X” offers the suave bass and catchy quality of “Magic,” a major single from “Ghost Stories,” but again, the lyrics stumble over themselves. Though the track is obviously intended to have a hands-in-the-air kind of groove, phrases like “I’ve got a rocket ship I want to ride” kill the mood.

Thankfully, the album ends on a satisfying note, with a run of back-to-back bubblegum sweetness. “Amazing Day” feels like classic Coldplay, with Martin’s slightly hushed vocals bringing back the emotions of singles like “Fix You.” The usual acoustic guitar and piano base are also seasoned with this album’s sunshine synthesizers.

After another introspective interlude — the minute-long instrumental “Color Spectrum,” represented on the album’s track list as simply a bar of color with no words — the album soars into “Up&Up,” its final track. Though the lyrics are borderline naive at times, the song has the kind of infectious can-do spirit that will leave listeners smiling. Celebrity collaborator Noel Gallagher of the band Oasis lays down an inspirational guitar riff in the bridge as Beyoncé and a choir, including Martin’s own children, help bring the track to its climax.

This sweet and simple button seals up an album that is childlike in its whimsy and wonder, evident even from its cover design. “A Head Full of Dreams” is bound to put a smile on your face with its uplifting spirit. It doesn’t necessarily offer anything new; it’s the same old Coldplay we know and love glossed with a modern pop sound. Yet there’s something in the album’s enduring positivity that makes it a gem.