What is Quadio?  That's the question currently being posed by the fine folks over at Rhino.com.  For an answer and some fun interactivity, click here.  But in short, Quadio describes the new series of four-channel audio DVDs (or "Quadradiscs") being introduced by Rhino with the reissue of 1969's Chicago Transit Authority, the first album by the band later known simply as Chicago.

This release is a landmark in a number of ways.  For one thing, it signals a new attempt to court the dedicated niche market of audiophiles largely ignored by the major labels when they abandoned the high resolution, multichannel formats of SACD (Super Audio CD) and DVD-Audio.  Secondly, it's one of the few modern reissues of an original quadraphonic, or four-channel, mix.  Finally, the audio is presented in both DTS 96/24 and Dolby Digital, both playable in virtually all DVD players, to reach the largest number of interested customers without requiring any special hardware.  Quadraphonic never caught on in the way stereo did, but in its 1970s heyday, literally hundreds of renowned rock, pop, jazz and soundtrack albums received the "quadio" treatment.  With this format largely forgotten today, the amount of unheard mixes of familiar albums is staggering and long overdue for reissue.

CTA is a stunning offering, and a fantastic way to kick off the Quadradisc series.  Long before "Hard to Say I'm Sorry" or "You're the Inspiration" cemented Chicago's reputation as purveyors of 1980s AOR pop, the band then known as Chicago Transit Authority was breaking new ground with an exciting fusion of jazz and rock.  The seven-man ensemble, along with producer James William Guercio, offered something for everyone in their sprawling double-LP debut: big, hook-filled pop singles ("Does Anybody Really Know What Time It Is?" and "Beginnings," both penned by frontman Robert Lamm), heavy blues-rock (the wailing "South California Purples"), political agit-rock ("Someday (August 29, 1968)") and even seven minutes of avant-electric guitar (the aptly-named "Free Form Guitar," courtesy of the band's incendiary Terry Kath).Suffice it to say that if you didn't own the original quadraphonic LP (Columbia GQ-33255, issued in 1974), you've never heard CTA quite like this.  With four speakers ideally placed in the four corners of a room, quadraphonic mixes were usually very discrete: vocals from one speaker, instruments spread out among the other three speakers.  CTA is no exception.  Sitting in the center of a room equipped with a multichannel setup, you will feel as if the band is literally around you, creating a fully-immersive listening experience.  In multichannel, the blazing horn section of Lee Loughnane (trumpet) and James Pankow (trombone) plus Walter Parazaider on woodwinds sounds punchier than ever.  Lamm's keyboards sparkle, and the guitar and bass attack of Terry Kath and Peter Cetera are sharp and stinging, with Danny Seraphine's tight drumming more revealing than ever thanks to the discrete, separated mix.  Vocals are most often up front and spread between the front right and front left channels, as quad utilizes no center channel as a 5.1 mix would.  Seraphine's drums are usually up front, too, with the horns, woodwinds and backing vocals mainly in the rear channels.  Even a familiar song can sound surprising when one instrument appears, isolated, in one channel, such as the guitar in the left rear channel of "Beginnings" or Pankow's trombone in the right rear for "Does Anybody Really Know What Time It Is?"  There are fun effects when handclaps move from channel to channel in "Listen" and vocals do the same in "Poem 58."

The original gatefold LP is lovingly reproduced in a cardboard mini-sleeve, which arrives in a re-sealable plastic cover.  There are unfortunately no liner notes discussing the quadraphonic mix, but there are new credits for Robert Vosgien's remastering and Bill Inglot's supervision of the Quadradisc series.  Two small gaffes slipped past Rhino's quality control: the indexing for Tracks 10-13 has been confused, with Track 10 including both "Prologue, August 29, 1968" and "Someday (August 29, 1968)" and Tracks 11 and 12 spreading out one song, the nearly-fifteen minute jam "Liberation."  In addition, the disc itself and back cover both indicate the release as DVD-Audio, but this release is actually standard DVD-Video and not the DVD-A format.  You don't need to be an audiophile with a high-end system to appreciate CTA; any basic home-theater setup with four speakers will allow for fun listening.

Still, this disc hasn't been without its share of controversy.  Audiophile message boards are ablaze with complaints that DTS 96/24 isn't lossless like true advanced resolution audio formats DVD-Audio and SACD.  Some have decried the use of an actual quad mix, wishing that Rhino had instead created a new 5.1 channel mix to take full advantage of modern surround-sound setups with center channel and subwoofer.  (Chicago II (Rhino R9 73841) and V (Rhino R9 73842) were both released in DVD-Audio in full 5.1, and are now out-of-print but not impossible to find.  Both sound exquisite.)  Still others are unhappy that a high-resolution stereo mix of the album wasn't included on the DVD.  I've found many of these gripes to be unfounded.  While DTS 96/24 does lack the extreme crispness of DVD-Audio and SACD, and I would have welcomed a release in one of those formats, the disc still offers splendid sound.  Robert Vosgien has addressed sound quality concerns at popular surround-music site quadraphonicquad.com by saying that DTS 96/24 "sounds very close to my original 96k/24 bit files."  As far as 4.0 vs. 5.1, the original quad mix is like an authentic time capsule, and very welcome on DVD.  And while many audiophiles would jump at a high-rez stereo mix, such an undertaking would be a very different project than this dedicated Quadradisc.  (The original quad LP didn't include the stereo mix; this is a straight reissue of that 1974 release, and is aimed at the multichannel market.)

To any fan of multichannel music, Chicago Transit Authority's Quadradisc is a must-purchase. Vosgien has also reported that Rhino is considering up to sixty more titles for Quadradisc release including albums by Jethro Tull, the Doobie Brothers, Black Sabbath and Yes.  Any subsequent releases, though, are contingent on sales of CTA.  More Chicago quadraphonic mixes also reside in the Rhino vaults, as all of the band's albums through X, save the live LP IV, were issued in the format.  Vosgien confirmed that Blu-Ray is a possibility for further releases, and unlike DVD, Blu-Ray would allow for true lossless audio.

Does anybody really know what time it is?  If it's time to take the plunge into quadio, you can buy the initial DVD release exclusively from Rhino.