I hear it's a very good place to start...ok, bad joke. I know.
So I had this great idea for a blog (basically, "the a cappella guide to singing") and no idea where to start. There's so much I could talk about in regards to singing- technique, breathing, flexibility, vocal health, etc- but I finally decided to start where every rehearsal, lesson, audition, or gig starts, warm ups.
Now I have heard every argument in regards to warm ups ranging from your singers should come to rehearsal already warm and you shouldn't waste your time to you're not spending enough time warming up and it should be a bigger focus in rehearsal. My acalosophy training has taught me to be somewhere in the middle.
In my experience most a cappella rehearsals are at night or late afternoon, so your singers have been talking for hours and their voices are generally warm. Therefore, I see just doing vocalises as a waste of time. Why not use the first 15-20 minutes of rehearsal or your assigned "warm up time" actually being productive? Why not take areas that you will work on in your music later and find a way to address them during warm ups? You can use this time to focus on blend, vowels, diction, breath control, dynamics, anything you'd like really.
I like to start my rehearsals with just 2 vocalises, usually one up and one down. But I never ever ever let any exercise focus on just one thing. Not only should this time warm up your voices, it should engage your ears, mind and muscles overall to practice good technique rather than becoming lazy and singing on autopilot. So with these vocalise, I usually ask to get muscles moving. Do some arm stretches, roll your shoulders, roll your head around, get your mouth moving. For example, here is one of my favorites:
I like to keep it simple singing scale degrees 5-4-3-2-1 on "mm" or a hum, descending by half step each time. Trick is, I ask for what I like to call "peanut butter mouth", singing like you literally have peanut butter stuck to the roof of your mouth. In theory, this is really going to get your mouth moving and loosen those muscles in your face. But, like I said, I'm a fan of multi-tasking. So while you're getting your mouth moving, lead some arm, neck and shoulder stretches. Tension in your muscles only leads to more tension and ultimately pain, especially after carrying it for 2 hours of singing.
Vocalises are just the beginning, now is when you do the real work. Is your group having blending problems? Use this time to do exercises that force your singers to open their ears and match vowels. (However, I wouldn't suggest actually using the word "blend" in rehearsal. Singers should trust their bodies and their natural core tone and "blend" may have your singers subconsciously sacrifice that tone to attempt to match someone else's.) One that I like is:
Voice 1: 5 - 5 - 5 - 5 - 5
Voice 2: 5 - 4 - 3 - 2 - 1
Voice 3: 1 - 2 - 3 - 4 - 5
Voice 4: 1 - 1 - 1 - 1 - 1
With Voice 4 being the lowest voice and Voice 1 being the highest, the chord changes are sung on "Mah Meh Mee Moh Moo" and you really can't let your group move on to the next chord until the one you're on is locked. Once you've mastered that, you can use this one exercise for a myriad of common a cappella group pitfalls.
Dynamics: Tell the group to sing each chord on half notes and change the direction of dynamics each time., e.g. start forte on the first chord and decrescendo to a piano by the last chord or start piano and crescendo to a mezzo-forte then sforzando on the last chord. Switch it up, make it a challenge, and make it fun and engaging for your singers.
Phrasing: Give phrasing and breathing directions. e.g. sing each chord on a half note and make every 4 beats a phrase. Don't breathe between the first 2 phrases, but breathe before the last chord.
Breath Control: Each chord should be a whole note. Have your singers take a good, deep breath for 4 beats and then attempt to get through the entire exercise without taking another breath.
Basically what I'm saying is to find exercises you like, and figure out how to apply and adapt them to become teaching models for things you'd like to accomplish in rehearsal or just to improve your group. Those are the best warm ups, the ones that subconsciously teach your group something while getting things moving, so later on you can say, "Remember when we were warming up and I asked for that really fast crescendo? Do that here."
Warm ups shouldn't be a passive or neglected activity, they DO serve a purpose much greater than just warming up your voices. This is a group so think of it more as warming up the group, putting all of the pieces together to get the group to function as one.
But Lo, it's right before a gig and people were late and we have 5 minutes to warm up, what should we do? First of all, people shouldn't be late, BUT my go-to is lip trills. Lip trills not only warm up your voice, they loosen the muscles in your face, force a steady stream of air and breath control because your lips won't buzz without air, and immediately engage your diaphragm. It's a good way to say, "Ok body, it's time to sing."
To be honest, contemporary a cappella is derived from choral tradition, and who did choir better than Robert Shaw? So here is The Choral Warm-Ups of Robert Shaw. Check these exercises out, they will definitely help with group continuity and building your group sound and overall musicianship.
I have so much more to say on warming up and building your group sound, but for now try (or at least think about trying) some of these techniques and see if they work for you.
Until the journey continues...