Line-up changes are common within huge rock bands, but after someone leaves a band, it's very rare for them to ever rejoin. Here are seven musicians who rejoined their bands after leaving.

1. Pat Smear - Foo Fighters

Former Germs guitarist Pat Smear received his greatest mainstream exposure when he joined Nirvana as a touring guitarist in 1993, which lead to his role in Dave Grohl's Foo Fighters starting in 1995. Smear's initial tenure in the Foo Fighters was short lived, performing with the band for the last time in 1997 at the MTV Video Music Awards, but he would eventually rejoin the band in 2007, bringing a three-guitar line-up to the band.

2. Christine McVie - Fleetwood Mac

Though Fleetwood Mac's classic Rumours line-up reunited for the first time in 1997, keyboardist/vocalist Christine McVie announced her departure from the band in 1998, which was later revealed to be due to her intense fear of flying. However, McVie would return to Fleetwood Mac in January 2014, with plans to release a new album with the band at some point in the near future.

3. John Frusciante - Red Hot Chili Peppers

Think of all of the Red Hot Chili Pepper's biggest hits: "Under the Bridge," "Give It Away," "Scar Tissue," "Dani California," etc. What these songs all have in common in that they were written with guitarist John Frusciante, who joined the band in 1988 and played on two albums, Mother's Milk and Blood Sugar Sex Magik, before leaving in 1992. He was replaced by Jane's Addiction guitarist Dave Navarro for one album, but returned for 1999's Californication, the band's biggest commercial success. Frusciante left the band for a second time in 2009.

4. Bruce Dickinson & Adrian Smith - Iron Maiden

Bruce Dickinson and Adrian Smith weren't original members of Iron Maiden, but they were members of the band during its classic years, playing on all of the band's best albums like The Number of the Beast and Powerslave. However, Smith would leave the band in 1990 due to creative differences with bassist Steve Harris, with Dickinson following in 1993. Both would rejoin Iron Maiden simultaneously in 1999.

5. Rob Halford - Judas Priest

When vocalist Rob Halford left Judas Priest in 1992, the band made a decision that could be seen as either brilliant or desperate: they replaced him with Ripper Owens, the lead singer in a Judas Priest tribute band named British Steel. Owens sang with the band from 1996 to 2003, until Halford decided to reunite with his old band.

6. Vince Neil - Mötley Crüe

Based on the previous two entries, there seemed to be a trend of heavy metal vocalists leaving their bands in the early '90s, and Mötley Crüe was no different. Vocalist Vince Neil left the band in 1992 (or was fired, as he claims) and was replaced by John Corabi for one album, 1994's Mötley Crüe, which was poorly received. Neil eventually rejoined the band in 1997.

7. Simon Gallup - The Cure

Though Robert Smith has been the only permanent member of the Cure, the second longest serving member of the band is bassist Simon Gallup, who joined in 1979, just in time to perform on the band's second album Seventeen Seconds. Gallup would leave the band in 1982 after a fistfight with Robert Smith, but would rejoin in 1984 and remain in the band to this day.

What other musicians have rejoined their bands? Let us know in the comments section!