In radio, talking over the start of a song and ending right when the lyrics kick in is called "hitting the post" and sometimes it's done without prewritten copy, just winging it.
It's just a skill you can practice and some people get quite good at it.
One difference with this is if you miss the lyrics, you can just try again next time. There's a new song every few minutes.
At my college radio station, every applicable record had intro time cues written on a label on the record jacket. You would know that there was, say, seven seconds you could talk over before the song began in earnest.
"Hitting the post" (not familiar with the term) was not really a problem for the deejays.
p.s. - I loved being able to inject our call letters into the gap on 'Riders On the Storm', timed to the top or bottom of the hour.
I get that it probably wasn't in the production schedule, but strictly speaking they could have come back a couple weeks later and done the shot with the voyager 1 launch.
It's just a skill you can practice and some people get quite good at it.
One difference with this is if you miss the lyrics, you can just try again next time. There's a new song every few minutes.
There was only ever one launch of Voyager 2.