I have a Pokemon with the "Festival Lead" Ability in the Active Spot. If I have more than one Thwackey in play, can I use more than one "Boom Boom Groove" Ability in the same turn?
Yes. Each Thwackey can use their Ability once.
Source: Twilight Masquerade FAQ; TPCi Rules Team (2024-05-23)

Relevant cards

Note: All applicable cards may not be listed below.
SV6_15
SV6_15
SV6_18
SV6_18
SV6_44
SV6_44
SV6_89
SV6_89