Musical.ly was a popular social media platform, particularly among teenagers, known for its lip-syncing videos. It was launched in August 2014 and gained significant popularity over the years. However, in August 2018, Musical.ly was acquired by a Chinese company called ByteDance and merged with their existing app called TikTok. The merged app was then rebranded as TikTok, which is the platform we know today.

Before the merger, Musical.ly had amassed a considerable user base. According to reports, by the time of the acquisition, Musical.ly had over 100 million monthly active users (MAUs) worldwide. These users were primarily from the United States and other English-speaking countries, but the app had gained popularity in various regions globally.

It is important to note that after the merger, all the existing Musical.ly accounts and content were migrated to TikTok. Therefore, the user base of Musical.ly essentially became the foundation for TikTok's initial user base. TikTok continued to grow rapidly, and as of October 2021, it has become one of the most popular social media platforms globally, with over 732 million MAUs.

Unfortunately, due to the lack of specific data on the user base of Musical.ly at different points in time, it is challenging to provide a more detailed breakdown of the user numbers before TikTok took over. However, it is evident that Musical.ly had a significant user base, and its merger with TikTok played a crucial role in the latter's rapid rise to prominence.

References:

1. "Musical.ly, the lip-syncing app loved by teens, acquired for $1bn" - The Guardian

(https://www.theguardian.com/technology/2018/nov/09/musically-acquired-tiktok-bytedance-lip-syncing-app)

2. "TikTok User Statistics 2021" - Oberlo

(https://www.oberlo.com/statistics/tiktok-users)