For those of you who don't follow the adventures of Tony Shalhoub's lovable obsessive-compulsive detective, a quick background:
Sharona Fleming, the title character's former nurse, will make her first appearance in five years. Bitty Schram portrayed Sharona for the show's first three seasons, only to leave after a contract dispute in 2004. Since, Traylor Howard has filled the role of her replacement, Natalie Teeger.
Despite the change in cast, "Monk" has remained a staple of USA's programming and one of cable TV's highest-rated series.
That isn't always the case when a program makes a key change in its cast.
Sometimes, shows survive just fine. "Archie Bunker's Place" enjoyed a successful run following the loss of its beloved Edith after the series' original form as "All in the Family"; "Three's Company" was a ball again after the departure of Suzanne Somers (and the Ropers); and, "Alice" still served up laughs (and Mel's questionable cooking) after the defection of Flo.
Other times, the exit of a main character is too much for viewers to handle. See "Head of the Class," "The Dukes of Hazzard" or "Saturday Night Live," whose fortunes have fluctuated depending on the appeal and starpower of its ensemble.
So, what does "Monk" (and the fun of '70s/'80s television) have to do with current music?
More than one band has recently scaled Billboard's charts as fronted by a non-original lead singer. As with a television cast, does a change atop a group's lineup spell a downturn in its popularity? Or, is an act's product, not necessarily its main voice, ultimately a better predictor of a band's sustained success?
Let's look at how certain acts have fared after replacing their lead characters. (We'll bypass bands whose histories have been well-documented for decades - Chicago , Journey , Van Halen  - in favor of those who've recently released new music and/or made headlines).
Alice in Chains 
Following the passing of Layne Staley, the band has returned with new lead singer William DuVall. Its new album, "Black Gives Way to Blue," is off to a strong start. The set debuted at No. 5 on the Billboard 200 two weeks ago, and its first single, "Check My Brain," has become the band's first No. 1 on Alternative Songs.
The venerable rockers also sport a new lead voice, with Kelly Hansen having replaced Lou Gramm. Two weeks ago, Foreigner notched its highest-charting album on the Billboard 200 since 1988 and returned to the Adult Contemporary after an absence of 14 years.
The Black Eyed Peas 
It's easy to forget that the quartet that has spent a full six months atop the Billboard Hot 100 this year released two albums, in 1998 and 2000, before adding a new principal that catapulted it to superstardom. It wasn't until 2003 that the Black Eyed Peas broke through at pop radio with "Elephunk," featuring the vocals of newly-added Fergie.
Other bands brought in new singers that transformed them into chart forces, such as No Doubt  (Gwen Stefani), Dixie Chicks  (Natalie Maines) and Sugarland  (Jennifer Nettles). Promoting from within has also worked. New Order 's Bernard Sumner replaced the late Ian Curtis in the wake of the band's Joy Division days, and Genesis ' Phil Collins added lead vocals to his drumming duties following the exodus of Peter Gabriel, and each group won new fans in both rock and pop audiences.
Gin Blossoms 
A variation on a change in a band's main voice: the still-active group - it recently released a live album featuring many of its '90s gems - has long sported Robin Wilson on lead vocals, but its original primary creative force was songwriter Douglas Hopkins, who died from a self-inflicted gunshot wound in 1992 before "Hey Jealousy" and "Found Out About You" made the group a favorite among fans of jangly modern rock.
When the final chapter closed on Hopkins' songbook, however, Gin Blossoms turned a new page and enjoyed further success with tracks written by other band members. The group reigned at radio with "Til I Hear It From You" in 1995 and "Follow You Down" in 1996.
Post-"American Idol," Adam Lambert not only was rumored to become the lead singer of Queen, but the group's Brian May publicly stated that the band would like to collaborate with the glam-rock rookie in some form. Such a union has yet to materialize, and billboard.com reported yesterday  on the leaking of Lambert's new solo single.
Lambert's not the first artist, however, to be linked to an established band. If speculation had been fact, Eric Clapton  would have replaced the late Roy Orbison  in the Traveling Wilburys , Julian Lennon  would have sung alongside Paul, George and Ringo and Terence Trent D'Arby  would have fronted INXS following the death of Michael Hutchence.
Speaking of INXS, how else but a reality show for a band to find a new lead singer in the 2000s? The group staged "Rock Star: INXS" in 2005, and winner J.D. Fortune won the contest and a spot center stage with the veteran act. With Fortune on lead vocals, INXS subsequently released the single "Pretty Vegas" and posted its first top 40 hit on the Hot 100 in 13 years.
The partnership has since ended, however. According to recent reports , Fortune has left the band on less than friendly terms.
The Jacksons 
We'll never know what a reunion might have been like between the Jacksons and their original member that left for the most thrilling of solo careers. Still, the entire Jackson 5 appears together on this week's Adult Contemporary chart for the first time since 1970.
See tomorrow's Chart Beat for more on the bow of "This Is It" at No. 19 on the genre airplay list.
Ultimately, there seems to be no one formula as to whether a band can successfully navigate a change in lead singers.
Perhaps it's simply the magic of music and those who make it that dictate whether the chemistry will work for its members, and, just as importantly, its fans.
(And, hopefully the connection that first made "Monk" a well-loved series earlier this decade will be there when Mr. Monk Meets Sharona once again).
- Chart Beat