However, there are differences. In a discussion about denominational differences, you mentioned that some churches use music and others do not. If this is a denominational distinction, then among the Catholic Churches there are differences which are just as serious, if not more so, than playing or not playing music in church.
Some Catholic churches say the filioque in their creed, others do not.
Some Catholic Churches use leavened bread, others use unleavened bread.
Some Catholic Churches crown the married couple, others will not have the crowning ceremony.
Some Catholic Churches confer confirmation at the time of baptism, others wait later at about 12 or 13 years old.
Some Catholic Churches have only icons and not statues, others allow statues.
Some Catholic Churches do not use the guitar in their services.
Some Catholic Churches receive Communion with a spoon, receiving both the Bread and Wine at the same moment.
Some Catholic Churches will allow married men as priests, others not.
Some Catholics believe in limbo, others do not.
Some Catholics believe that the fires of purgatory are equal to the fires of hell, others do not.
Fasting regulations differ between Catholic Churches of different traditions.
Some Catholic Churches have an altar rail, others do not.
Some Catholic Churches allow Communion in the Hand, others do not.
Most people are going to say that these do not constitute denominational differences. Similarly, the differences that you have mentioned, such as whether or not to play music during church services, are not enough to define a “denomination.”
Since you have not adequately defined what you mean by a denomination and shown that this definition is acceptable to the parties concerned, any attempt to justify the number of denominations at 43000 is unconvincing.