1. Go to YouTube and search for "Jab Hum Tum Suhani Background Tune."
2. Click on the first result, which should be an official upload by Sony Music India.
3. Click on the three dots in the bottom-right corner of the video player.
4. Select "Download."
5. Choose the audio format you want (MP3 or WAV) and click "Download."
6. The background tune will be downloaded to your computer.