To disable MoH for one user or a group of users, perform these steps:
1. Define a Media Resource Group (MRG) without any MoH resources, and put that group
into a Media Resource Group List (MRGL)
for the users that you want to deny MoH access.
2. Put the MoH resource into a MRG, and put that group into a MRGL for the users
that you want to permit MoH access.
For further reference use the following document: Cisco Unified MeetingPlace, Release 7.0 -- Configuring Cisco Unified Communications Manager: Music On Hold http://docwiki.cisco.com/wiki/Cisco_Unified_MeetingPlace,_Release_7.0_--_Configuring_Cisco_Unified_Communications_Manager:_Music_On_Hold