Read tis fm another thread ... no need another song for champagne pouring???
We would recommend to use the same music throughout the March-In till Cake-Cutting or Champagne pouring. Reasons being;
a) A change of songs within a short span of 3-5mins can be distracting, if the songs selected have different tempo, beat, rhythm and etc.
b) A change of songs would also mean a need for change of CD, which means a possibility for human error. Thus, in our opinion, we would want to minimise such possibility. Though nowadays, most people have CD burner, thus, point (a) would come in for consideration.
c) If for any reason(s) that you really want to have 2 pieces of music to be played during the March-In and Cake Cutting/Champagne pouring, then I would advise that you asked your videographer (if you have engaged one) to assist you to 'fuse' the 2 music together, such that the transition of the 2 music can be continuous rather than an abrupt stop and start.
As for whether people notice the music played, generally most people would for your 1st March-In, but by the second march-in... most guests would be concentrating on their food and chit-chats