Over time there have been several boardwalks in Ocean City. In 1905 a new 2-mile stretch was completed with a new Municipal Music Pavilion, opening in August of that year. It served as an attractive venue for musical performances or a great place to just relax and enjoy the view. At that time it sat where the Moorlyn Theatre sits today, and the boardwalk sat where the theatre parking lot is.
The pavilion was expanded at some point--I haven't quite figured out when--but sometime during the 1920's.
When the fire of October, 1927 burned most of the boardwalk, but spared the pavilion, it was moved to around 6th street. It later burned down in 1965.
The new Music Pier that we see today was completed in 1929.
Here are a few views of the old and new piers: