The most popular acts at this year’s CMJ Music Marathon — such as Tapes ‘n’ Tapes on Wednesday at Bowery Ballroom or the Decemberists on Friday at Hammerstein Ballroom — do not lend themselves as fully to CMJ’s “new music first” ethos, so you may be better off heartily embracing the unfamiliar on offer, visiting venues you’ve rarely (if ever) been to, and seeing bands whose songs you can’t sing.

Of course, exclusively seeing bands you’ve never heard of doesn’t promise to be much more fun than standing in line for tickets. You must have at least the semblance of a plan.

Label showcases are a good way of mixing up acts you know you want to see with others you don’t know but could conceivably like. The week is full of them. If you missed Japan’s always outstanding Deerhoof when they came through New York last year, you’ll want to check them out at the Kill Rock Stars showcase on Friday at Webster Hall. It also includes a performance by Brooklyn noiseniks Excepter. (Webster Hall also will host British dance faves Hot Chip and the spastic Brooklyn art rockers Gang Gang Dance on Thursday, as well as the Fall on Saturday.)

Friday’s Merge Records showcase at the Knitting Factory will feature the full-size rock of White Whale and Portastatic’s pretty songs, among others, while the experimental mainstay Tonic will host the most promising showcases, with Bar/None on Wednesday, Thrill Jockey on Thursday, Jagjaguwar on Friday, and Social Registry on Saturday.

Label showcases make good sampler platters, but you’ll need a full course or two to get your healthy fill of the marathon. Up-andcoming bands worth checking out include Portland, Ore., natives the Thermals, whose new album (their third) is their best yet. Don’t worry about getting into their Thursday show with the Shins at Bowery Ballroom; instead, catch them at the new Greenpoint, Brooklyn, club Studio B on Friday. Elsewhere, the new indie-pop act from North Carolina, the Annuals, is getting plenty of Arcade Fire-esque hype for its debut, “Be He Me”; catch one of its three shows this week: Wednesday at the Syrup Room, Friday at Bowery Ballroom, or Saturday at the Annex.

The much loved Virginia hip-hop duo Clipse will perform songs from their overdue second album (which is finally scheduled for late November) on Saturday at the Knitting Factory. The show offers a chance to check out Houston rapper Trae, as well as Naledge and Double O, in their new act Kidz in the Hall, whose debut is out today. For more alternative hip-hop, check out Strange Fruit Project and others at Southpaw on Friday night. There is also a chance to see the mash-up master behind Girl Talk, Gregg Gillis, practice his vicious art at the Mercury Lounge on Wednesday.

The Scandinavian Invasion is practically an indie institution at this point, and while it would be difficult to do CMJ this year and not see a few obscure Norwegian or Finnish acts, the one most worth seeing is the Swedish brother-sister duo the Knife, on Wednesday at Webster Hall. Getting in may prove an endurance test, but their party Goth is worth the effort.

kyarnell@nysun.com