You put on a record and lie back down to read your book. The first song ends and one you like a little less comes on, but your bed is comfortable and you know track three is an old favorite of yours. Pretty soon, you’ve listened to one whole side of the disc.

Those days may be gone. MP3s and iPods have led to a new way of listening to music commonly described as “music A.D.D.” Sufferers of this malady can have difficulty listening straight through an entire album, sometimes even an entire song.  Fortunately, modernity has provided the antidote to its poison in the form of mash-ups.

Mash-ups alleviate the symptoms of “music A.D.D.” by allowing you to listen to at least two songs at once. The Best of Bootie 2005 is a collection of twenty mash-ups produced mainly by California DJs. Bootie is a three-year-old San Francisco dance club that has been instrumental in popularizing the mash-up format.  Two important cautions, however: remember that mash-ups are only as enjoyable as the original songs, and avoid the accident of thinking a mash-up is the original song. It has a similar effect to drinking orange juice when you’re expecting milk.

Most of the DJ names on The Best of Bootie 2005 sound like screen names a middle schooler might concoct, but don’t let that fool you into thinking these guys are amateurs. Some keep it simple, mixing only two songs such as Cheekyboy’s “Smells Like Compton,” which meshes an unlikely pair of ’90s hits: N.W.A’s “Straight Outta Compton” and Nirvana’s “Smells Like Teen Spirit.” Another unusual rap-rock combination is Party Ben’s “Paid for My Doorbell” which consists of Eric B. and Rakim’s “Pump Up the Volume” and The White Stripes’ “My Doorbell.”

Many tracks seem intent on creating a bridge between the past and current music. Jay-R’s version of The Ramones’ “Rock and Roll High School” includes M.I.A. as the band’s lead singer, spouting the lyrics from “Galang.” The two songs with their distinct energies and brands of hedonism really complement one another.

Other blends, such as “Somebody Rock Me” are aurally appealing but meld songs as thematically disparate as “Rock the Casbah” and “Somebody Told Me.” This shortcoming is slightly irrelevant, though, if like these DJs your number one priority is to get on the dance floor and start your hips gyrating.

Some DJs are minor alchemists, stirring fizzling vats of pop culture and producing small nuggets of danceable ore. But others contribute tracks to this album that paint them more as matchmakers cum clerics, uniting beats and lyrics in a matrimony that seems destined, whether or not the original artists knew it.

Thriftshop XL shifts back and forth between bits of Franz Ferdinand’s “Do You Want To,” Run DMC’s “It’s Tricky” and The Knack’s “My Sharona.” An entirely new song is born from this union, and listening to the component songs individually after hearing the mash-up will cause you to try and slide them back together in your mind like puzzle pieces.

Loo & Placido work together some Kelis and Black-Eyed Peas to showcase their combination of the Beatles’ “Run for Your Life” and Ludacris’ “Fatty Girl.” John Lennon’s possessive jealousy and Ludacris’ tail-chasing sit side by side with arms on each other’s shoulders. The track also chomps at the bit with schizophrenic energy.

Despite being a fresh, creative outlet, mash-ups are illegal for the obvious reason that they are usually made without the permission of original artists. Some DJs bring the art of collage to the world of music purely for entertainment purposes, but others have an additional agenda. They are defiantly combating corporate impingement on freedom of expression, such as EMI’s famous outlawing of The Grey Album, a series of mash-ups from the Beatles’ White Album and Jay-Z’s Black Album. The illegality of mash-ups gives the music consumer the advantage that they are offered for free online. The Best of Bootie 2005 is available at www.bootiesf.com/bestofbootie_2005. You can fight corporate bigwigs and the symptoms of “music A.D.D.” all while getting your groove on.