"That is an album of their concert."
Translation:Tiu estas albumo de ilia koncerto.
tio is for some unspecified thing with no referent. Here, the reference is "albumo", so it needs to be
tiu. Unless it's a human being, in which case you would also just use
- "I see that [unspecified thing]" would be "Mi vidas tion".
- "I see that dog" would be "Mi vidas tiun hundon".
- If we were talking about something and I see the very thing we're talking about, I could say "Mi vidas tiun".
- If there is no referent but someone uses
tiu, then it's referring to a person. "Kiu estas tiu" = "Kiu estas tiu [homo]".
So it's not quite a matter of pronoun vs adjective.
I think "el" is only used when something has moved physically from one place to another. If you are talking about an album that was at the concert and you got it there, and took it with you, you can say el. However, I think this specific sentence isn't about an album that physically was at the concert, but rather contains the music that was recorded at the concert.