Himesh has made use of terrific INTENSE harmonium piece at HIGH SCALE in some of his songs:

Kuch Toh Baaki Hai from Milenge Milenge

The well-structured catchy harmonium theme piece at a LOWER scale used intermittently throughout the song jumps/shifts to a TERRIFIC INTENSE HIGHER SCALE near the end i.e. only lower scale from 3.30 to 3.34, the higher scale joins in from 3.34 to 3.38 and completely dominates and takes over from 3.38 to 3.46 whereby it is in full form and gives JAZBA to the listener, thus making for an intense semi-classical outing.

Damadji from Radio

Terrific intense harmonium piece at higher scale from 1.52 to 1.55

Other places (i.e. non high scale / non intense:

Wada Tenu from Aap Ka Suroor

Used intermittently throughout in both original and unplugged version.

Dhoom Tere Ishq Ki from Karzzzz

Used intermittently throughout the song.

Chalao Na Naino Se Baan Re from Bol Bachchan

The banarasi babu harmonium piece from 2.30 to 2.37 & 3.55 to 4.03

Ishq Mein Ruswa from Dangerous Ishhq

The harmonium theme piece from 0.22 to 0.33