I recently came across this interview of T.R. Balamani of Bombay. She is an extremely experienced teacher, and many of her students have become not only performers but superstars. Among her students are Shankar Mahadevan and Bombay Jayshree.
One of the things that I found interesting was her emphasis on varnams. She has her students practice varnams in multiple kalams and nadais, and said that everything you need to understand about music performance can be found in varnams. This is interesting because we often like to learn a lot of songs, but she says that focusing on basics is really how you improve. In my own teaching I have found it to be true, and here is why.
Each varnam goes into depth in that particular ragam. It shows a variety of patterns and gamakams and emphasizes the important phrases in the ragam. It allows the student to learn how to sing anything in that ragam in slow and fast speeds. It gives a lot of practice in voice control while teaching about expected patterns. I have noticed that whenever I teach a varnam, by the time we get to the end the student can almost read the music and sing without my having to teach, because they have understood the essentials of the ragam.
Varnams by their nature are rhythmic. In addition, they utilize different rhythmic patterns and are sung in two speeds. They are fantastic practice and allow the student to become proficient in laya.
Because of the way varnams stretch words across many notes, it has the same effect as practicing akara sadhana. This encourages students to learn very precise voice control. Switching notes when you have a word on each note is not as difficult as correctly hitting all the notes when you do not have a word to anchor you. In this way, varnams take the music student to the next level.
By the same token, varnams provide an opportunity to practice each syllable in isolation – not mixed up with a lot of notes. This helps students understand how to use correct pronunciation while singing. Correct pronunciation allows for listeners to understand the lyrics and enjoy the music more. For the singer, it makes akarams (and eekarams, ookarams, etc) easier if the vowel sound is correct.
In addition to sections with lyrics, there are sections of a varnam that are just swarams (note names). This helps the student study swarams and their patterns. It lays the foundation for kalpana swarams and gives the student a deep understanding of the ragam. It helps the student understand in a deeper way the relation between the names of the swarams and the sounds that they make. And finally, the student learns to switch between swarams and sahityam (lyrics) with ease.
Varnams are special in one more sense. While they are exercises that are used as a tool for learning and understanding music, they also are concert-worthy pieces. Many concerts open with a varnam and they are even more difficult than many krithis. They are an essential part of learning music. A consistent focus on varnams gives students a stable foundation and allows them to handle basically anything in music.