A charity wants you to play a last-minute benefit concert as part of a fundraising effort to help keep the doors open. That means it’s time to get the band back together, and you have very little time to track them down and start rehearsing.

Okay, so that’s roughly the plot of “The Blues Brothers,” but the movie portrays a hyped-up example of the stresses of putting together a last-minute gig. It also offers some clues to help anyone faced with such a predicament.

First and foremost, you need those who know you best to back you up. You need your band, or those side men and women who have backed you up in the past, to help pull off a last minute gig. If they aren’t available, every town has a cadre of session players. Get to know as many great musicians in your area as possible, because they will more than likely be willing to help you out when you’re in a bind.

The best way to put together a show on short notice is to always heed the motto of the Boy Scouts of America and “Be Prepared.” You should always have your equipment ready to go and be in a constant state of practice.

Your band may not have played a show in months, but you should always be rehearsing. If that’s not an option, keep recordings of all your live performances on hand. In a crunch, the band can always turn to them for clues and mental reminders on what and what not to do. Barring having those live recordings, give the musicians your CD/demo and tell them “We’re playing it just like this,” so they can rehearse on their own at home.

If there are problem areas that need to be worked through and you can’t all get together in person, try working through them on a speaker phone conference call.

When you’re looking to fill out a set out but don’t have much rehearsal time, that can be problematic. Bring on the cover songs! Everybody loves a good cover song and every musician worth his or her salt knows the classics of whatever genre they play in. “Louie Louie,” “Sweet Home Alabama,” sit-com theme songs, whatever. If you know basic I-IV-V chord structure you can play pretty much anything in the pop realm. Even if the band doesn’t know all the specific notes and changes, they still can “fake it to make it,” as the saying goes. If you make a mistake, just keep on playing instead of showing frustration. You could even deliberately make the same mistake again, to make it seem like it was a planned. Like Marty McFly in “Back to the Future,” take charge of the situation. You should feel comfortable saying things to the band like, “Alright guys, this is a blues riff in B. Watch me for the changes and try and keep up.”

The bottom line is you need to be able to quickly adapt to changes and improvise. Practice daily, even when no gigs are on the calendar. Help to avoid a last-minute gig disaster by immersing yourself in music, keeping all your equipment and instruments in ready-to-go-on condition and keep practicing and rehearsing with others on a regular basis, whether you’re in a band or not. Surround yourself with great musicians who love to play for the sheer joy of playing and you’ll be ready for prime time when that time unexpectedly comes.