This week in Alternative Music, the National plays on The Tonight Show with Jimmy Fallon; Park's And Recreation recruits alternative bands for their season finale; New photos from Kurt Cobain's crime scene emerge and a new single from the Black Keys.

On March 27th, The National was the musical guest on The Tonight Show starring Jimmy Fallon. According to Pitchfork, the band has been traveling through the US to publicize their documentary Mistaken For Strangers. The film debuted at the Tribeca Film Festival however it will be released into theaters on March 28th.

Watch the The National play "This is the Last Time" from their Grammy-nominated album, Trouble Will Find Me below.

NBC comedy show Park's & Recreation, will recruit some popular alternative rock artists for their season finale. Rolling Stone reports that the concert themed episode will feature Yo La Tengo as a Night Ranger cover band, The Decemberists, Letters to Cleo and even Jeff Tweedy, the front man for Wilco. Many of the artists will be in disguise but fans may be able to recolonize them. The episode will air on April 24th.

As the 20th anniversary of Kurt Cobain's death nears, new photos of the crime scene have emerged from the Seattle Police Department. Many people speculate that the case will reopen, however, CBS News reports that the authorities have no intention of reopening the case. The 35 photos have never been seen by the public. In fact, they remained undeveloped until a recent inquiry into the musicians death investigation.

Private investigator, Tom Grant, who was hired by Courtney Love just days before Cobain's death commented on the delayed actions of the Seattle Police Department. "I think they are going to regret that they said that sooner or later," says Grant, who told CBS News that he thinks they rushed to the conclusion that Cobain's death was a suicide.

Finally, the Black Keys have released a new single from their 8th studio album, Turn Blue. "Fever" is accompanied with a video of hypnotizing swirls of pink and blue line that continue to spin through the clip. This single is the first official song from the album which will be released on May 13th.