Christmas concert in 2013 that I was asked in a primary school includes the involvement of 94 children of five classes (from first to fifth) of the only section of the school.
There is no path to long-term, it is a short route with defined goal but precise: to involve all children (without exception) in a public concert of Christmas.
In the second lesson, conducted in each class, check the level of acquired skills of intonation of children. Therefore, listening to the children divided by rows of benches (and thus for groups of six to eight children at a time) and within these individual groups, listen to them also further divided into groups of two or three at a time. Obviously, feeling more exposed to the public opinion, children are more timid, but verification is equally effective. Only in some cases I can also listen to individual children (in this case, the exposure is too high and shyness prevails).
The exercise is based on the first four sounds of the tune "Silent Night", without words. It is a central tessitura and a pattern familiar to all:
Typically, the intonation is too low (only in rare cases is increasing); it can also happen that they perform successfully, but an octave lower. Start from sound that children spontaneously emit and from there back to the sound it proposed.
Based on this simple assessment, you can divide the class into three groups: 1) group of children that show an immediate security of intonation; 2) group of children a little uncertain (or shy), considered likely to improve with practice; 3) group of children who have more difficulties, for which we would need more time to learn and practice specific, targeted.
After evaluation, it's back to sing the whole class to complete. The next lesson, we will try to guide the children in the group 1 to the singing, the other to the rhythmic section. Each group will work with specific exercises for the task that will have been addressed. Children in group 2 will eventually be re-evaluated before deciding on the final location. It being understood that there may be scenarios elastic, because, for example, the children of group 1 may also want to make the rhythmic section! But meanwhile it is an initial sorting.
Obviously, this does not mean that the rhythmic part is easier, but it definitely is a step preparatory to the use of the vocality, as well established in the music education.