as Fleetwood Mac's 2009 Unleashed tour and No Doubt's 2009 Summer Tour. In another case, artists embark on a concert tour to celebrate the anniversary of their past albums, such as U2's 2017 tour to mark the 30th anniversary of The Joshua Tree (1987) and Janet Jackson's 2019 tour to commemorate the 30th anniversary of Janet Jackson's Rhythm Nation 1814 (1989). Farewell tour A farewell tour is a concert tour intended to signal the retirement of a singer, a disbanding of a band, or the end of a show's run. Many of the tours end up not being the last tour, with frequent regroupings, or revivals of shows. Luciano Pavarotti's 2004 tour and Kenny Rogers's 2015–2017 tour are examples of farewell tours which were the last to be staged before their deaths. Revenue , the highest-grossing concert tour of all time is Elton John's Farewell Yellow Brick Road, which is an ongoing tour from 2018 to 2023, with a gross revenue so far of $817.9 million. In second place is Ed Sheeran's ÷ Tour, with a gross of $776.2 million. The third-highest-grossing concert tour of all time is U2's 360° Tour, which earned approximately $736 million between 2009 and 2011. Madonna's Sticky & Sweet Tour, which earned $408 million in 2008 and 2009, was the highest-earning tour by a female artist. According to the 2014 report from Billboard Boxscore, five acts made over US$1 billion in touring since 1990: The Rolling Stones, U2, Bruce Springsteen, Madonna and Bon Jovi. Global touring revenue reported to Billboard Boxscore exceeded $5.5 billion in 2016. Due to the collapse of record sales in the 21st century, concert tours have become a major income for recording artists. Besides the tickets, touring also generates money from the sales of merchandise and meet-and-greet packages. However, the touring business suffered in the early 2020s because of the COVID-19 pandemic. Pollstar estimated the total lost revenue for the industry in 2020 at more than $30 billion. Response The mobility of concert tours requires a lot of costs, time, and energy. It is very common for musicians to not see family members for over a year during their touring. British singer Adele expressed her unhappiness of concert tours, saying "Touring is a peculiar thing, it doesn't suit me particularly well. I'm a real homebody and I get so much joy in the small things." A concert residency concept is offered