Duff McKagan is the founding bassist of Guns N’ Roses and the leader of Seattle’s Loaded. His column runs every Thursday on Reverb.Seattle’s KEXP radio station at 90.3 FM remains a one-stop destination for those music appreciators who like a bit of everything: new, old, indie, not-so-indie, metal, old punk, electronic, rockabilly, alt-country (and all of that just on the drive home from the grocery store). KEXP really does play alternative in its truest sense: the alternative to everything else on the radio.”Alternative music” is a moniker used primarily for marketing purposes in 2013.I spent about a week last summer mountain climbing with a male 20-something. He was constantly listening to his iPod with headphones, and I finally asked him what music he was listening to. He replied “Alternative music”. I asked this fella who the artists were, and he remarked: “You know…Linkin Park, Evanescence, Red Hot Chili Peppers, and that stuff.” I pressed on, inquiring about how he found these bands all to be “alternative.” I, of course, am thinking that all of these bands are majorly mainstream, and far from any alternative to what is mainstream. I stated as much to my friend. He looked at me weirdly, and then answered that “alternative” is how iTunes categorically lists these bands. My friend will simply look at what is “alternative” first in the iTunes store, and then make his purchases off of that list.He is from a smaller city in California, and hence, probably is much more a voice for the “regular” American music listening populace that doesn’t live in places like Seattle, San Francisco, and New York.Anyhow, back to KEXP and further to the fact that they are celebrating 40 years in existence this year. Of course, before Paul Allen infused some well-placed dough into the station-and thusly changing the name to KEXP (an Experience Music Project nod),the call letters were KCMU. The affiliation with the University of Washington still remains, and so does its mission statement of playing new music, mixed with just about everything else…those harder to find tracks or artists that may never have found the light of the radio airwaves without a station like this.Punk rock, new wave, post-punk, reggae, and Tom Waits-ish types were the alternative to everything else back in 1979 when my friends and I first started listening to KCMU. It was our station, and the UW students who spun the records had an uncanny ability to kind of mind-read what those of us actually in the young music scene in Seattle wanted to hear. We felt lucky to have the station.I actually remember one day listening to KCMU during a dry-wall job I had and the DJ proclaimed for the first time that KCMU played the music that “is the alternative to everything else on the FM or AM dials.” I like to think that I was actually a listening-witness to the first time in history this term was used. KEXP has remained a great place to hear new music, and to re-visit an old Buzzcocks gem…or even hear some Prince or Solange Knowles segue into a bit of the Deerhoof. There are specialty shows for heavy-metal and rockabilly and live performances in-studio, and on and on. The “alternative” mission statement has remained adhered to there at KEXP.And now, my eldest daughter listens to KEXP. She is 15, and KEXP is what the cool kids this age apparently listen to. At 40 years running, KEXP has officially become generational with Seattle families such as mine.