It's not quite a harmonic convergence, but Saturday's 10th annual Joni Mitchell birthday concert at Dizzy's by Robin Adler and Dave Blackburn qualifies as a convergence in harmony. The addition of singer John Quint opens the door to three-part vocal harmonies that should suit Mitchell's luminous music especially well.

Mitchell, who turns 73 on Sunday, is recovering from an aneurysm she suffered in early 2015. Saturday's tribute to her comes just three days before the culmination of the most contentious presidential election in memory. The concert will provide timely political commentary, through the prism of her songs (ticket information appears below).

It is billed as "Joni Mitchell: Prophet of Our Times, Songs of Social Justice." The set list includes such Mitchell classics as "Woodstock" and "Big Yellow Taxi." But the focus is largely on songs she recorded between 1985 and 1994, beginning with her high-tech "Dog Eat Dog" album and running through "Turbulent Indigo."

This represents a shift for the gifted musical team of Adler and Blackburn. The married couple's previous Dizzy's shows have seen them and their band, Mutts of the Planet, perform such landmark Mitchell albums as "Blue," "For the Roses," "Court & Spark," "Hejira" and "Mingus," in their entirety.

"Joni had a lot of opinions about politics, America and the way things were being handled under President Reagan," Blackburn noted. "We decided to focus on that part of her work because we haven't done it before and because of the election."

The songs Adler, Blackburn and Quint will perform Saturday include "Passion Play (When All the Slaves are Free)," "Sex Kills" and the title track to "Dog Eat Dog."The concert's newest selection, 2007's "Shine," contains such prophetic lines as: Shine on rising oceans and evaporating seas / Shine on our Frankenstein technologies.

Mitchell announced her official retirement in 2007, following the release of her "Shine" album. She had stopped touring in 2000 due to a variety of factors, including her disillusionment with the music industry and her afflication with Morgellons disease, a painful skin condition. Her last San Diego performance was in 1983 at the Civic Theatre.

But the impact of her music continues to be felt far and wide, directly and indirectly, through the work of such disparate Mitchell admirers as Björk, Taylor Swift, former San Diego troubadour Jewel, Ellie Goulding, JAmes Blake, Sara Bareilles, Tool singer James Maynard Keenan, Diana Krall, Laura Marling and many more. Prince, who died in April, often cited Mitchell's 1975 opus, "The Hissing of Summer Lawns," as one of his all-time favorite albums.

Adler and Blackburn flew to Canada in September to perform at Joni Fest, a private, invitation-only event that celebrates Mitchell's rich artistic legacy.

The couple's annual birthday concerts at Dizzy's in her honor have perodically featured former Mitchell band members, most notably bassist Max Bennett. Saturday's tribute in a trio format will be a compartively stripped-down affair, although it may well sound like more musicians are playing than will be visible on stage.

Blackburn, the concert's only instrumentalist, will use three acoustic guitars, including a bartione model, in three different tunings. He also employs a variety of effects pedals to trigger everything from swelling orchestrations to a mellotron, the early sampling instrument prominently used in the second half of the 1960s by The Beatles, Rolling Stones, Moody Blues and other bands seeking to expand their aural horizons.

"On the more mellow songs by Joni, I have 'Strawberry Fields'-like flutes I trigger with my guitar. On 'Sex Kills,' I have these angry-sounding horns," said Blackburn, who is happy to use sleight of hand (or, rather, foot).

"When you take a horn patch and drop it down a couple of octaves, it doesn't sound anything lke a horn. I play acoustic guitar and use all these effects, (including) two pedals board, tied together. So the gap is bridged between it being an acoustic instrument and sounding kind of produced."

For the supple-voiced Adler, the challenge is to phrase Mitchell's often dense lyrics in a way that lets listeners savor each of Mitchell's poetically crafted words.

"It's very important to me that people are able to hear the lyrics. So I do my best to emphasize them, without being stiff," Adler noted.

"In some cases, I've come up with my own phrasing. Because Joni sometimes is very wordy. And some of her lines are pretty heavy, like - in 'The Magdalene Laundries' - These bloodless brides of Jesus / If they had just once glimpsed their groom / Then they'd know, and they'd drop the stones / Concealed behind their rosaries / They wilt the grass they walk upon / They leech the light out of a room / They'd like to drive us down the drain / At the Magdalene laundries.

Adler cites Mitchell's "Dog Eat Dog" album for inspiring her to become a professional singer. She has since immersed herself in Mitchell's music and read nearly everything available about the iconic troubadour to further her understanding of the songs.

"Joni would acknowledge that a lot of her songs are conversational, and that's an interesting way to approach a song," Adler said.

"I memorize all her lyrics, rather than read any of the words as I sing them. And I am even more enthusiastic about her music now than when we started doing these birthday concerts 10 years ago."

"Joni Mitchell: Prophet of Our Times, Songs of Social Justice," performed by Robin Adler, Dave Blackburn and John Quint

When: 8 p.m. Saturday
Where: Dizzy's (inside the San Diego Jet Ski Center), 4275 Mission Bay Drive, Pacific Beach
Tickets: $20 at the door
Phone: (858) 270-7467
Online: dizzysjazz.com
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george.varga@sduniontribune.com