The Grammys have yet to overcome their lack of diversity, but music’s other conferrer of ultimate honors, the Rock and Roll Hall of Fame, initially showed an impressive color blindness. Its inaugural batch of inductees — the Class of ’86 — included 10 “performer” acts, and six of them were black.

The next year, 15 performers got in, and two-thirds of them were black. While this is admirable, it’s also undeniable: Artists become eligible for induction 25 years after the release of their first recording, and the Rock Hall paid appropriate homage to the true architects of the genre, most of whom happened to have been black.

Over the years, voters recognized practically every major black talent in music up to the 1970s: Barry White, The Commodores, Dionne Warwick, The Fifth Dimension, Rufus featuring Chaka Khan, the Spinners, and War still could use some Hall of Fame love, but the elite club deserves major props for welcoming non-crossover black artists like Bobby Womack and Solomon Burke when pop radio rarely did.

Recently, though, black representation among the inductee classes has been waning and lacking. This year’s group is one of the best this decade, with The Cure, Def Leppard, Janet Jackson, Roxy Music, Stevie Nicks, and The Zombies officially joining the hallowed ranks tonight in Brooklyn. Of those seven performer inductees, only one, Jackson, is black.

The token black nominee has become a Hall of Fame tradition since 2015. Last year’s was Nina Simone. The year before, it was Tupac Shakur. The year before that, it was N.W.A, and Bill Withers launched the trend in 2015. The previous year the inductee class was 100 percent white for the third time this century, following 2003 and 2008.

What happened to the Rock and Roll Hall of Fame that used to recognize black talent so enthusiastically? Maybe its ardor peaked too early: So many vintage black icons were crossed off the to-induct list in the ’80s and ’90s that this century has been largely about giving second-tier legends their due.

Another explanation might be evolving critical attitudes toward black music. Artists who debuted around 1975 and weren’t eligible for the Hall of Fame until the turn of the century emerged at a time when white critics largely had lost interest in R&B and were focused on punk, new wave and other subgenres of rock.

The mid-’70s also marked the beginning of R&B’s decline in the pop mainstream. Less than a handful of black acts that debuted in the latter part of the decade have scored a spot in the Rock and Roll Hall of Fame. Donna Summer took 14 years of eligibility. Prince took one. Chic, one of the premiere groups of disco, is still waiting.

Artists who released their first albums in 1980 have been eligible for induction since 2005, and only six black inductees who debuted after the ’70s —  Grandmaster Flash and the Furious Five, Run-D.M.C., Public Enemy, N.W.A., Tupac Shakur and Janet Jackson —  have received invitations. Three times as many white performing acts from the same era have gotten in, including pop-punk trio Green Day, grunge trio Nirvana, white rap trio Beastie Boys, and four Class of 2019-ers: The Cure, Def Leppard, Radiohead, and solo Stevie Nicks.

With Janet Jackson as the lone black female inductee from after 1980 alongside a series of male MCs, two things are clear: 1) Black female performers never have been more undervalued than they have been from the ’80s on; and 2) The future of Rock and Roll Hall of Fame-worthy black music is rap.

Disco may have been to blame for the lower level of respect lavished on black music after the ’70s halfway mark. It was generally dismissed as a throwaway gay and black phenomenon, it was reviled by the ’70s-era rock intelligentsia that still dominates the Rock Hall gatekeepers, and as its popularity peaked, music became increasingly segmented, often along color lines. For more than eight years — June of 1982 to October of 1990 —  Billboard’s Hot R&B/Hip-Hop Songs chart was known as Hot Black Singles, and there was often little overlap between number ones there and on the Hot 100.

First, radio reflected the change, and later, MTV followed. Some of the most influential acts to emerge in the late ’70s and early ’80s, before Michael Jackson’s “Thriller” made pop radio once again safe-ish for black artists, struggled to crossover to the pop market. Teddy Pendergrass never enjoyed a top 10 solo pop hit single, and neither did Rick James. Luther Vandross famously never made it to No. 1. None of them have been nominated for the Rock and Roll Hall of Fame.

Some black artists continued to sell well beyond the disco era, but only a handful sold consistently in the pop market in the ’80s. Those who did — like Lionel Richie and Whitney Houston — often made creative concessions (sing whiter and act it, too) in order to grasp mass appeal. By the ’90s, Boyz II Men, Mariah Carey, TLC, and Toni Braxton were raising black music’s mainstream fortunes, but white critics usually ignored them, and it feels pretty safe to assume the Rock and Roll Hall of Fame will, too.

It wasn’t until rap started to emerge as a mainstream force in the late ’80s and ’90s that black artists once again became a regular presence on critical hit lists. Of the four black acts to win the Album of the Year Grammy since 1999, two of them (Ray Charles and Herbie Hancock) debuted well before the ’80s and two (Lauryn Hill and OutKast) were rap/hip-hop artists.

If you’re a black singer from the post-disco era, patience is indeed a virtue when it comes to Album of the Year (ask Beyoncé) and the Rock and Roll Hall of Fame. Janet Jackson was eligible for 11 years before nabbing her spot. Last year, her “Poetic Justice” costar Tupac Shakur was inducted posthumously in his first year of eligibility, as were Grandmaster Flash and the Furious Five in 2007, Run-D.M.C. in 2009, and Public Enemy in 2013.

Now that rappers are among the most commercially viable acts in music, enjoying longer careers and getting glowing reviews commensurate with those lavished on the masters of rock, are they the Rock and Roll Hall of Fame’s great black hope? Jay-Z won’t be eligible until 2021, Missy Elliott until 2022, and Kendrick Lamar until 2036, so we’ll have to wait and see.

Sisters and brothers with voices might never again enjoy the recognition the Rock and Roll Hall of Fame showered on them during its early years, but it might be up to rappers to ensure they continue to get invited to the party.