Last summer, when my best friend from high school (and one of the youngest members of our class) turned 40, I made what I thought would be the last in a series of 40th birthday gifts that began when my brother hit that milestone a few years ago.

It turned out that I wasn’t done after all, as another friend’s birthday celebration last month gave me cause to extend the series by one. But on the chance that I’m truly done now, I want to spread the word about how I went about making these gifts because — regardless of how much they were enjoyed by the recipients — I had a heck of a good time putting them together, and I thought some Bartography readers might get just as big a kick out making some themselves.

I’ve long loved compiling music CD for my friends and family, especially mixes with some sort of theme. I find the process to be a lot like writing and editing, in that there are lots of considerations of tone and pacing and length, plenty of opportunities for humor and history and poignancy, and — of course — painful decisions about what to keep and what to cut.

About 4 1/2 years ago I stumbled into the knowledge that a carefully assembled mix of songs representing each year since a person’s birth — given the average length of songs in my library — came out to exactly the right length to span two CDs commemorating that person’s 40th birthday. That’s 41 songs, actually, when you include one from the year the recipient was born and one from the current year.

I had a lot of 40th birthdays coming up among people I cared about, and I loved the idea of crafting for each of them a unique two-CD set of songs I thought they in particular would enjoy. What I didn’t much care for was the prospect of combing through 10,000 or so songs each time a pal or a cousin had the big 4-0 coming up.

So — and this took exactly zero twisting of my own arm — I spent a lot of time listening to the songs in my collection from 1968-2008 and picking 10 from each year that I wanted to be on my master list, the list from which I’d select the tracks for each person’s mix. For the sake of variety and out of my love of a good challenge, I limited the master list to one song per act. And 10 songs was a hard and fast rule — I could add something new to the list for a particular year, but something else had to go. I could pick from 410 songs, and not one song more, and when another calendar year rolled around, it was time to come up with 10 more songs for the master list. January birthdays were kind of a pain, but having to come up with 10 great songs by as-yet-unrepresented artists for each new year sure kept my ears open.

There were loopholes, sure — in addition to a Beatles track, for instance, there were solo recordings by John and George and one by Paul in his collaboration under the name The Fireman. (Sorry, Ringo.) Jack White was in with the White Stripes but also singing a duet with Loretta Lynn, and Aimee Mann was in there both solo and with ‘Til Tuesday. A Nina Simone song remixed years after her death got included posthumously. A mashup of Madonna and the Sex Pistols and another of the Beatles and the Wu-Tang Clan made it in there not for the years of any of the original recordings but for the years when the DJs in question worked their magic.

And to my mind, there was indeed magic — threads and conversations and references I hadn’t planned on made themselves known as I put the mixes together or played them back to myself. There were Dusty Springfield and Patti Smith covers of Van Morrison, and Maria McKee and Allison Moorer covers of Dusty Springfield and Patti Smith. One mix might have a song by Charley Pride, one where he’s name-checked by songwriter Steve Goodman (“You Never Even Called Me by My Name”), Goodman’s own recording of a song made famous by Arlo Guthrie, and covers by Sharon Jones and Wilco of songs written by Arlo’s dad, Woody. Careful ears would hear echoes of Mantronix’s “Needle to the Groove” in Beck’s “Where It’s At,” and regardless of whether a listener knew that Billy Bragg’s “A New England” had been covered by the writer of Tracey Ullman’s “They Don’t Know,” they still got a couple of good tunes.

And the recipients heard only part of the story. What they couldn’t know just from listening were the memories of mine that surfaced as I put these songs together — my own recollections of where the songs came from, who gave them to me, or what they meant to me the first time I heard them or during the times in my life when they were in heavy rotation. Likewise, I hope, some of these tracks may have had lives of their own beyond my knowledge as my friends shared them with others after their birthdays.

Like those songs, I could go on. Or, just to give you a clearer idea of what these gifts sounded like — and what you might be treating your friends (and yourself) to if you decide to give this idea a try — maybe I’ll just leave you with the track listing of my final mix. So far, anyway…

1972 – I Saw the Light – Earl Scruggs
1973 – Three is a Magic Number – Bob Dorough
1974 – Loving Him Was Easier (Than Anything I’ll Ever Do Again) – Tina Turner
1975 – New Suit – The Wild Magnolias
1976 – Once I Had A Love – Blondie
1977 – Knockin’ Lost John – The Band
1978 – The West Texas Waltz – Joe Ely
1979 – Better Not Look Down – B.B. King
1980 – Shut ‘Um Down – Gil Scott-Heron & Brian Jackson
1981 – Medley: The Running Kind / I’m A Lonesome Fugitive – Merle Haggard
1982 – I’m Movin’ On (Live) – Emmylou Harris
1983 – A New England – Billy Bragg
1984 – An Elegant Chaos – Julian Cope
1985 – Don’t Slander Me – Roky Erickson
1986 – Sonia – Sonny Memorial Quartet Clark with Ray Drummond, Wayne Horvit
1987 – Mr. Brownstone – Guns N’ Roses
1988 – (Waltz Me) Once Again Around the Dance Floor – k.d. lang
1989 – Hey Ladies – The Beastie Boys
1990 – Rise From The Ruins – Mark Heard
1991 – Second Chance – The Reivers
1992 – Let The Mystery Be – Iris Dement
1993 – My Baby Don’t Dance to Nothing But Ernest Tubb – Junior Brown
1994 – The Change – Steve James
1995 – Motor Away – Guided By Voices
1996 – I Feel Alright – Steve Earle
1997 – Sab Vird Karo Allah Allah – Nusrat Fateh Ali Khan
1998 – Baltimore Fire – Kate & Anna McGarrigle
1999 – In My Hour Of Darkness – The Rolling Creekdippers
2000 – Love Me Do – Flaco Jimenez
2001 – Summer Days – Bob Dylan
2002 – Feel – Robbie Williams
2003 – I Believe in a Thing Called Love – The Darkness
2004 – Garbage Day – The Ike Reilly Assassination
2005 – This Land Is Your Land – Sharon Jones & The Dap-Kings
2006 – Everyone’s in Love – Will Kimbrough
2007 – Violeta, Diamond of the Everglades – Li’l Cap’n Travis
2008 – Sing The Changes – The Fireman
2009 – A Little Bit Of Mercy – Caroline Herring
2010 – Don’t Look Back – She & Him
2011 – One For The Dance Halls – Jesse Dayton
2012 – Come On! – The Hives