Krom tio, ke la interakto estos mallonga, ankaŭ orkestro ludos.

As a fixed expression, krom tio, ke means something like besides the fact that..., apart from the fact that..., or in addition to the fact that....

It is made up of:

• krom = besides, apart from
• tio = that, that thing
• ke = that, introducing a clause

So Esperanto is using a structure like apart from that, that..., which sounds more natural in Esperanto than it does literally in English.

Ke introduces a subordinate clause, just like that in English.

Here, the clause is:

la interakto estos mallonga

So krom tio, ke... means besides the fact that...

Without ke, the sentence would not connect properly to the full clause that follows.

Esperanto usually separates subordinate clauses with commas.

Here, ke la interakto estos mallonga is a subordinate clause inserted after krom tio. The commas help show where that clause begins and ends:

• first comma: before the ke-clause
• second comma: after the ke-clause, before the main clause continues

So the punctuation makes the sentence structure easier to see.

Mallonga is built from:

• longa = long
• mal- = the direct opposite

So:

• longa = long
• mallonga = short

The prefix mal- is very common in Esperanto. It often creates the opposite of a word.

Examples:

• bona = good → malbona = bad
• granda = big → malgranda = small
• longa = long → mallonga = short

Because mallonga is an adjective, and adjectives do not take tense endings.

To say will be short, Esperanto uses:

• estos = will be
• mallonga = short

So:

• la interakto estos mallonga = the intermission/interval will be short

You cannot put the future ending -os on mallonga, because -os belongs to verbs, not adjectives.

La means the, so la interakto refers to a specific, known intermission/interval.

But orkestro appears without la, which usually makes it indefinite:

• orkestro ludos = an orchestra will play / there will be an orchestra playing

Esperanto has no separate word for a/an, so a bare noun often has that indefinite sense.

So the contrast is:

• la interakto = the intermission/interval
• orkestro = an orchestra

Here ankaŭ means also and adds another piece of information.

The idea is:

• besides the intermission being short,
• also an orchestra will play

Its position before orkestro makes the sentence feel like also, an orchestra will play.

Word placement with ankaŭ can affect nuance. For example:

• ankaŭ orkestro ludos = also, an orchestra will play
• orkestro ankaŭ ludos = the orchestra will also play

Those are close, but not exactly identical in emphasis.

Because there is no direct object here.

In Esperanto, -n usually marks:

1. a direct object
2. direction toward somewhere

This sentence has neither.

The main nouns are subjects:

• la interakto = subject of estos
• orkestro = subject of ludos

And mallonga is a predicate adjective after esti, so it does not take -n here.

Ludos is the future tense of ludi (to play).

Esperanto verb endings are very regular:

• -as = present
• -is = past
• -os = future
• -us = conditional
• -u = command/wish
• -i = infinitive

So:

• ludas = plays / is playing
• ludis = played
• ludos = will play

Because the two predicates are different types.

• estos mallonga uses the verb esti plus an adjective
• ludos is a normal full verb by itself

So:

• la interakto estos mallonga = the intermission will be short
• orkestro ludos = an orchestra will play

Both are future in meaning, but they are built differently because one says will be + adjective, while the other uses an ordinary lexical verb.

Yes, to some extent. Esperanto word order is fairly flexible, but changing it can shift emphasis.

For example, this sentence could be rearranged in ways that are still understandable, but the original order is useful because it clearly presents:

1. the krom tio, ke... phrase first
2. the added main statement after it

The original version sounds organized and natural:

• first, a background/additional fact
• then, the main extra point

So while Esperanto allows flexibility, the given order helps the sentence flow clearly.