IT'S NOT just books you can't judge by their covers; it's also bands. Usually. But Washington's award-winning old-timey band, the Double Decker String Band, has decided to confuse the issue thoroughly. The cover of its new album, "Sentimental Songs and Old Time Melodies" (Fretless 160), makes it look like an oversized 78.

"That's our source, the old 78s," says Baltimore guitarist John Beam, who is also a free-lance graphic designer and part-time teacher at the Maryland Institute College of Art. "I have a stack of 'em here at the house. Fiddler Bill Schmidt and I were going down to practice in Washington one day the other half of the band, Bruce Hutton and Craig Johnson, lives in Takoma Park , and I said, 'Bill, I've got an idea for the record cover.' I took one 78 in its jacket and dropped it in his lap. He said, 'Yeah, so what?' I asked what the shape was. 'Square.' What's the shape of a 33? 'Square, just a little larger.' From there it grew."

Beam's design evolved after he looked at hundreds of old 78s. The flowery label design itself was inspired by the classic Vocalion center. "I got a sense of how they approached it: a great potpourri of typefaces, a lot of which didn't make much sense together. A lot of those old covers didn't look like there was much design attached to them, so I had this problem of trying to design and not design at the same time. I'm usually not so cavalier in my use of typefaces, mixing them, but that was fun."

The jacket design is also a compendium of details lifted from 78s of the '20s: "a record that should be played in every home . . . perfect reproduction on all phonographs . . . change needles regularly . . . electrically recorded." "In the old days that was the big deal, like nowadays they'd say 'digitally recorded,' " Beam explains. "This of course was to get people to buy the product because it was technically advanced at the time." The "all phonographs" warning was because different records often had to be played on different needles; Edison had one, Victor another. Even the speed would vary -- 78 was the aim, not the norm; there was no quality control back then, so the hand crank could determine the speed of playback . . . 80 . . . 78 . . . 81.

One modern concession: liner notes, which came in with albums. "Back then the covers generally had nothing to do with the actual material," Beam points out. "They were stock covers printed for a particular company, touting their reproduction process and company name. There was very little descriptive copy." What there was was confined to the label itself, as on Double Decker's: "old time string band with vocals . . . for listening and dancing." (The band performs classic tunes by such pioneers as Riley Puckett, Doc Roberts, Charlie Poole and Uncle Dave Macon.)

With the design in hand, Beam's next task was to re-create the classic brown "craft paper" look of the 78 jacket sleeves. There was nothing like it in printer's color samples, so Beam had to find an available brown and then add different percentages of black to create the necessary coarseness and hue. "I was taking a chance. The mechanical has six or seven overlays, which is very tricky for a two-color job. We paid almost what we would have for a four-color cover simply because the mechanical was so complicated. And you never really know if it's going to work, if it's going to be convincing, until you see what comes off the press, but the printer did a wonderful job on it."

Beam also designed Double Decker's first album cover, "Giddyap Napoleon," and had done several covers for friends in Baltimore. He reports, "Some people have told me they'd consider buying the record just because of its cover, and I've rarely heard that about an album. When I did, I thought, yeah, that's what design is all about. If I can do something like that, I have made a successful piece."