Workout thrice weekly. Forty-five minutes is enough.
Vocal rehearsals, lessons, and concerts count as workouts.
Warm-ups only remind you how you sing best. They will keep your voice in shape on quiet days and prepare your voice for busy days. By themselves, daily warmups won't make your voice strong, fast, flexible, enduring, or accurate. More on how to do these later.
Workouts will improve the voice, but only if you keep doing them. Doing just one workout a week is enough to tire you and get you some improvement, but several in a week will definitely improve your singing.
Please do not sing far too much. Singing when your voice and body are tired open the door to get bad technique and vocal injury. For beginners, three workouts a week is almost too much. As your voice gains strength and stamina, it will thrive on three to four or even more workouts weekly. Just don't push yourself too hard too fast. The above is going to get you where you want to go.
You'd think five vowels.. A E I O U, and sometimes Y (and even W) ... would be enough, but they are not. Dictionaries have pronunciation keys on most pages. They ALL have 12 or more distinct English vowel sounds. Wikipedia gives 30 different sounds in English:
ă pat, bad, cat, ran
ăr parry, carry
ā pate, bait, play, same
ä pa, father
är part, arm, bard, aria
âr pare, hair, pear, there, scary
ĕ pet, bed, bet, end
ĕr perry, merry
ē pete, ease, see
ĭ pit, sit, bit
i pee, midi, very, ready
ĭr pert, syrup, Sirius
ī pie, my, rise
îr peer, here, near, serious
ŏ pot, not
ō oat, go, hope, know
ōr port,hoarse, glory
ô paw, law, caught, saw
ôr horse, more, laureate
oi poi, boy, noise
o͝o, put, foot
o͝or, poor, tour,
o͞o, poo, lose, soon, through
ou pout, house, now
ŭ putt, run, enough, up
ûr purr, fur, bird
ə uh, about
ər per, enter
Critically, 30 vowels is too many. When I sing them out loud, long and slow, some of those those vowels sound the same to my West Coast USA ear: ä pa = ô paw, i pee = ē pete. (Say these out loud. Do you hear a difference? if yes, then it's two different vowels to your dialect of English. If not, it's all one.)
Further, some of those vowels are made by smooshing two other vowels, gliding one into the other (called diphthongs). oi poi = ō oat + ē ease. ou pout = ô paw + o͞o lose. Diphthongs are sung as one simple vowel (almost always the first one) followed briefly by another. Practice it by prolonging the first vowel, then second vowel is a quick glide away from the main vowel just before you make the next sound.
Then there is R which could get its own article... and will. Classical singers (and almost all other languages singers) treat R as a diphthong following the main vowel.
I go with a simpler list for practical purposes.
(this from http://en.wikipedia.org/wiki/English_phonology)
Lexical sets representing
General American full vowels
FLEECE GOOSE
KIT FOOT
FACE NURSE GOAT
DRESS STRUT THOUGHT
TRAP PALM
This list omits long i, while thought and palm are very similar in many English dialects.
Simple to think this way:
a e i o u, long and short, gets to ten (Face, fleece, Pie, goat, goose, palm, dress, kit, thought, foot) then add these three: Nurse, trap, strut
Since R in spoke English can change the vowel, so that's another 13 vowels you CAN learn, but they're rarely sung, even by American singers.
Exercises:
Do long tones on 13 different vowels.
Take any vocalize. Run in on 13 vowels.
