 To support Back to Basics ( 2006 ) , Aguilera embarked on the worldwide concert Back to Basics Tour . The tour received mixed to positive reviews from music critics ; The Georgia Straight 's Mike Usinger praised Aguilera 's vocals as " insanely powerful , " while Dave Simpson from The Guardian criticized the setlist as " confusing . " The show in Adelaide , Australia on July 17 and 18 , 2007 was filmed and was released as a DVD . 
