Robert Plant [ tickets ] and Alison Krauss [ tickets ] have extended their "Raising Sand" tour, with the unconventional duo now slating new shows well into fall.

The two vocalists--who continue the current leg of their North American tour tonight (7/14) in Toronto--have added nine new shows in September and October, kicking off Sept. 23 in Kansas City, MO. Details are below.

The pair will again be backed by a full band led by "Raising Sand" producer T Bone Burnett, with Plant and Krauss performing selections from their joint album, along with material from their respective catalogs.

Released last October, "Raising Sand" debuted at No. 2 on The Billboard 200 album chart. The set spawned the cut "Gone Gone Gone (Done Moved On)," which scored Plant and Krauss a Grammy in the Best Pop Collaboration with Vocals category in February.

In June, the pair received three nominations for Americana Music Association awards: Duo/Group of the Year, Album of the Year for "Raising Sand," and Song of the Year for "Gone Gone Gone." Winners will be revealed during the AMA's 7th annual awards show Sept. 18 in Nashville.

Plant and his surviving former Led Zeppelin bandmates--Jimmy Page and John Paul Jones--performed a one-off reunion concert last December in London as part of a tribute to late Atlantic Records founder Ahmet Ertegun. In May, Canadian music network Much Music reported that the band would shortly announce four additional reunion dates in Toronto, but the group's management quickly denied the rumor.