Can I use my phone during the concert?

Not while the music plays. At KalaSudha concerts, switch your phone off or set it to silent before the music starts, and leave texting until the interval.

The rule covers the whole concert, from the first note to the last. In a quiet hall, the musicians can see a lit screen from the stage.

Once the concert ends, take your phone out for photos and short clips: see Can I photograph or film the performance? For timing, see Is there an interval?