SXSW 2013 is in the books. In case you missed Dave Grohl’s keynote speech (either in person or online) and have 50 minutes to kill, it’s worth a listen — covering his personal history of bedroom multi-tracking at 12, his punk-rock cousin from Chicago who took him to see Naked Raygun, Nirvana being wined and dined by A&R guys, his devastation and musical recovery after the death of Kurt Cobain, and finding and keeping his “musical voice.”