I'm working through the Pimsleur German Course. The announcer explains the 'ins' construction as a contracted form of 'in' + 'das'. During a lesson, the announcer introduces the phrase 'to a concert,' and he translates it into German as 'ins Konzert'. For example, a sentence like 'But I prefer to go to a concert' is translated as 'Aber ich gehe lieber ins Konzert'. The source sentence contains an indefinite article, but the resulting one contains a definite article. This situation confuses me. Is this translation correct? Can you help me clarify my confusion?
I guessed that it could be a mistake, but there are several different sentences throughout the lesson that are translated in the same way.
The full sentence:
I like to go to the movies, but I prefer to go to a concert.
The suggested translation is:
Ich gehe gerne ins Kino, aber ich gehe lieber ins Konzert.
Another one:
You may invite me to a concert.
And the translation:
Du darfst mich ins Konzert einladen.