Academy Award winner Diane Keaton. A Chorus Line writer Nicholas Dante. Original “Turkey Lurkey Time” girl Baayork Lee. Ten-time Tony Award winner Tommy Tune. What do all of these artists have in common—beyond their status as theatrical powerhouses? They each performed in a Broadway ensemble 50 seasons ago.

While that proliferation of well-known performers gracing the upstage corners of Broadway stages may be surprising, it’s fairly easy to discover why: 73 productions opened during the 1967–1968 season on Broadway. The sheer volume is a marked difference from the 33 shows scheduled to open this season.

And that’s not the only difference in the Broadway ensembles of that season and this one, according to the Playbill Vault and analysis from The Ensemblist. (Though some things remain the same: Bernadette Peters was starring on Broadway that season, as well, opposite Joel Grey in the new musical George M!.)

In the 1967–1968 season, an impressive 259 ensemblists originated tracks in Broadway productions. It’s a striking number of jobs considering 165 ensemblists will originate parts in Broadway musicals this season. Still, the fact that 40 more shows opened 50 years ago, yet only about 100 fewer ensemblists worked on Broadway speaks to the increasing demands on each individual performer in today’s Main Stem landscape.

Read: THE 23 MOST-REVIVED MUSICALS INS BROADWAY HISTORY SINCE 1927

Across the boards, Broadway casts were larger. The largest ensemble was 42 performers in I’m Solomon and four other shows boasted ensembles of 30 or more in their casts. Today, zero productions include that many ensemble contracts. The largest chorus in a new musical this season will be seen in the Lincoln Center Theater revival of My Fair Lady with 29 on its roster.

Perhaps the most striking difference between ensembles then and now is what you don’t see onstage: the swings. These are actors who cover multiple ensemble tracks in a show. Today, approximately one out of every five Broadway actors are employed as swings. In 1968, only two actors were credited with the title: Katherine Hull, listed as Swing Girl in George M!, and Sammy Williams as the swing for The Happy Time. (He went on to create the role of Paul in A Chorus Line.) Yet this 2017–2018 season, 33 actors are billed as swings.

The proliferation of swings on Broadway is likely due to longer show runs. When a show runs for months and years, actors accrue vacation and sick days. Therefore, in a long-running show it’s more likely that the cast performing on any given night includes at least one swing.

Compare the multi-year runs inhabiting Broadway shows today. In the the 1967–1968 season, four of the 35 active Broadway theatres housed shows that opened the previous season or earlier: the Imperial (Cabaret), the Majestic (Fiddler on the Roof), the St. James (Hello, Dolly!) and the Winter Garden (Mame). Today, 11 of the now 41 active theatres have housed the same show for more than a year.

Another reason more individual actors worked as ensemblists 50 years ago? Despite the shorter runs of yesteryear, performers did not jump from cast to cast. According to Playbill Vault, only six actors appeared in multiple musicals that season—though it wasn’t impossible to do so. Actor John Dorrin opened two different shows in the spring of ’68: Saint Joan opened January 4, 1968 and closed February 10, in time for him to start previews for I’m Solomon on April 23.

So what’s the forecast for Broadway performers in the future? Nothing is for certain, but as longer runs with smaller casts become the norm for Broadway musicals, we are likely to see fewer actors on Broadway. However, as the length of time those actors are working on Broadway increases, we are more likely to see them blossom in other creative ways while maintaining a stable income and an artistic home under the lights of Broadway.

Mo Brady is co-creator of The Ensemblist.