Singing a capella refers to singing, whether in a group or solo, but without the support of musical instruments. Learning to sing a capella requires the basic foundation needed in most styles of singing and perhaps even more since a capella singers cannot rely on the instrumentation layer for accompaniment. There are things you can do to learn to sing a capella on your own, yet the expertise of a singing teacher can help you polish various subtleties you might not observe on your own. You will need to develop intonation, the ability to sing in key and learn to determine the tonality of a song based on a single pitch you hear. Additionally, learning to sing in harmony over a melody will help you significantly if you choose to join an a capella group.
Warm up your voice by doing proper breathing exercises, singing scales or other warm-up routines as indicated by your singing teacher.
Play a major or minor scale on your piano or keyboard, such as C major (C, D, E, F, G, A, B and C) or A minor (A, B, C, D, E, F, G and A). Listen to each note carefully and sing the note that matches the pitch you are playing. Use a piano or keyboard, if possible, because they are less likely to go out of tune than other instruments, such as a guitar.
Continue singing all the pitches that match the notes you play throughout the scales.
Play the note C on your keyboard and hum that note quietly prior to singing it at loud. Sing the whole C major scale slowly without playing any other keys on the keyboard.
Finish singing the C note and make sure your intonation is correct by confirming with the C note on the keyboard. Vary this exercise by ending on different notes within the key, then confirm correct intonation with the keyboard.
Play notes that are out of the scale at random and sing the matching tone even if it is in a different octave. This will help you train your ear to recognize different tones.
Singing in Key
Determine the section of a song you wish to practice singing a capella.
Play the root, the third and the fifth of the key in which the melody is to be sung. For example, play the notes "C," "Eb" and "G" on your keyboard if you will be singing "My Funny Valentine," since the song is in the key of C minor.
Continue singing a capella and occasionally play the appropriate chords on the keyboard as they correspond to the melody you are singing. This will help you determine if you are still singing in key or if you have deviated from the tonality of the song.
Find the Tonality
Think of a song you wish to sing. Determine if the starting chord of the song is major or minor in quality. Use your keyboard if necessary. Minor and major chords are determined by the interval between the root note and third note of the chord. The third note of a major chord is four half-steps above the root, such as the interval between C and E. The third note of a minor chord is three half-steps above the root, such as the interval between C and Eb.
Use a starting pitch as intonation support to begin singing a song. Play the note "A," for example. Sing a three-note chord based on that one note of support as explained below.
Quietly hum the tones "A," "C" and "E" to find the tonality of "A" minor. Quietly hum "A," "C#" and "E" to find the tonality of "A" major. Use your keyboard if in doubt. This will help you use any given note at random and find the quality of the harmony that fits the song you want to sing.
Sing out loud the three notes that form the starting chord for the song. This will help you recognize the tonality of the song. Begin singing a capella without additional instrument support.
Learn to Harmonize
Learn to recognize possible harmonies over a melodic line. For example, play the following notes for a sample melody on your keyboard: Bb C Db C Eb.
Play the sample melody a couple of times and sing it out loud until you have memorized it.
Play the sample melody one more time and simultaneously play the following notes: Db Eb F Eb Gb. These next set of notes correspond to higher voice singing an optional harmony for the original sample melody.
Play the original sample melody again. Simultaneously play the following notes: F Ab Bb Ab C. These new set of notes correspond to a lower voice singing an optional harmony for the original sample melody.
Play the original sample melody and simultaneously sing one of the proposed harmonies described in Steps 3 and 4. Continue playing the melody and singing one of the proposed harmonies.
Practice harmonizing the notes of scales. For example, play C, D, E, F, G, A, B and C on your keyboard and simultaneously sing E, F, G, A, B, C, D, E.
Try different harmonies over simple melodic ideas. Repeat this exercise as much as needed to train your ear to recognize harmonies in all sort of melodies.
Joining an a capella group can be one of the best ways of improving and learning. Record yourself as you sing a capella and listen to the recordings. This will help you determine where you need to improve.
Contact a singing teacher to get instructions on breathing, proper use of your voice and appropriate exercises.