Theory:

     Mahendran looked up, alarmed. He had just been sharpening his claws on the edge of the coconut shell. But worse than Ravi’s awful whoop EEK was a ‘Kreech...!’ from the window. What a weird sound! If Mridu was startled, M.P. Poonai was frightened out of his wits. Hair standing on end, he bounced up and scurried towards a bamboo tray of red chillies that had been set out to dry. Trying to hide beneath it, he tipped a few chillies over himself. “Mi-a-aw!” he howled miserably.

     The ‘kreeching’ went on and on. “What’s that noise?” said Mridu.

     “That’s Lalli learning to play the violin,” grunted Ravi.

     “She’ll never learn a thing. The music-master just goes on playing like a train whizzing on and on, while Lalli’s all the time derailing! Going completely off track!”
Explanation:
 
Due to Ravi's sound, Mahendran the cat, looked up with fright. The cat had been sharpening his foot nails on the edge of the coconut shell,  in which milk was served earlier. Ravi's shriek sounded bad and unpleasant, but there was a worse sound from the window "Kreech…!" It was a strange sound. Mridu was suddenly alarmed, but M.P.Poonai was severely shocked. His body hair stood up straight in the alarm! He jumped and moved hurriedly with quick short steps. He bumped on a tray of red chillies that had been set out for drying in the sun. Some chillies fell on him, and he shouted terribly.
 
chili-638457_1920.jpg
Chillies set out drying in the sun!
 
The "kreech…" sound from the window continued. Mridu asked what the noise was. Ravi replied in a low voice that Lalli was learning to play the music instrument violin. He added that Lalli would never learn to play the violin. He said the music-master played the violin very well that it sounded like how a train moves fast with a buzzing sound right on track; while Lalli's violin sounded like the train that got derailed, that is totally off the tracks.
 
violin.jpg
Lalli's violin sounded derailed!
 
Meanings of difficult words:
 
No.
Words
Meanings
1
alarmedfeel frightened, in danger
2
awful 
very bad or unpleasant
3
weirdstrange or unusual
4
startledfeeling or showing sudden shock or alarm
5
frightened out of witsterrify, panic suddenly
6
scurriedmove hurriedly with short quick steps
7
miserablypitiable, unhappy manner
8
whizzingmove quickly through the air with a buzzing sound
Reference:
National Council of Educational Research and Training (2007). Honeycomb. A Gift of Chappals - Vasantha Surya (pp. 18-32). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.