Anyone who is even remotely connected into the big concert scene in the Twin Cities has recognized that the Summer Concert Schedule for the Xcel Energy Center far outweighs that of the the Target Center.
Just for a starting point, the Target Center does not have a concert on the events calendar for over a month. The next Target Center Concert is Daughtry, on May 19th. In contrast the Xcel Energy Center has Taylor Swift, James Taylor and Brooks and Dunn all before that May 19th concert. There has been lots of speculation as to why the Target Center didn't pull in big names for the spring and summer concert series this year, everything from artists don't like the Target Center to the Xcel Energy Center has better sound... in my opinion those types of answers just don't float, the Target Center has had lots of great concerts many of which have been reported to have amazing sound.
I genuinely think that Target Field may be to blame... with such a focus placed on the Minnesota Twins this season and making sure that Target Field got off on a good foot, the Target Center took a back burner... understandable when you consider the full-time resident of the Target Center (the Minnesota Timberwolves) and their season end struggles. However, because of the Target Field buzz, Target Corporate may have to face some sad financial facts when the summer concert numbers come in later this summer.