Learn Hardcore Japanese: watasi no syumi ha ongaku de, sukina kasyu no konsaato ni tokidoki tomodati to ikimasu. - My hobby is music, and I sometimes go with friends to concerts of singers I like.

私の趣味
- 私 (I / me) + の + 趣味 (hobby)
- Here の marks possession or belonging: my hobby.
好きな歌手のコンサート
- 好きな歌手 (singer I like) + の + コンサート (concert)
- Here の again links two nouns, but the relationship is “X’s Y / Y related to X”:
  - 好きな歌手のコンサート = the concert of the singer I like / my favorite singer’s concert.

So in both places の links one noun phrase to another, but the exact nuance (ownership, belonging, “of”, “’s”, “related to”) is decided by context.

Why is it 私の趣味は and not 私の趣味が?

は marks the topic of the sentence; が marks the subject (often new or focused information).

私の趣味は音楽で、…
- 私の趣味 = “As for my hobby” / “Speaking of my hobby”
- This sets hobby as the overall topic, and then you tell us more about it.

If you said:

私の趣味が音楽で、…

It would sound odd here, because you’re not contrasting my hobby with someone else’s or highlighting it as new information; you’re just introducing the topic “my hobby” and describing it.

So in sentences like “My hobby is X”, は is the normal, natural choice:

私の趣味は料理です。= My hobby is cooking.
兄の趣味はゲームです。= My older brother’s hobby is games.

Why is it 音楽で instead of 音楽です?

音楽で is the て-form of 音楽だ / 音楽です.

音楽です。 = “(It) is music.” (polite, sentence-ending)
音楽で、… = “(It) is music, and …” (polite, but used to connect to the next clause)

So:

私の趣味は音楽です。
= “My hobby is music.”
私の趣味は音楽で、好きな歌手のコンサートにときどき友達と行きます。
= “My hobby is music, and I sometimes go to concerts of singers I like with my friends.”

Using ～で、 (the て-form of だ/です) is a common way to smoothly link two related statements in one sentence.

Why is there a comma after で: 音楽で、?

The comma just shows a natural pause where one idea connects to the next. Grammatically, the で at the end of 音楽で is already doing the connecting.

You could write it without a comma:

私の趣味は音楽で好きな歌手のコンサートにときどき友達と行きます。

but this is harder to read. The comma makes the structure clear:

私の趣味は音楽で、
好きな歌手のコンサートにときどき友達と行きます。

Commas in Japanese are often used more for readability and rhythm than for strict grammatical rules.

Why is there no 私 in the second part? Shouldn’t it be 私は…行きます?

Japanese often omits the subject when it’s obvious from context.

The first part already established 私 as the topic: 私の趣味は…
In the second part, it’s naturally understood that I am the one going to concerts.

Saying 私は好きな歌手のコンサートに…行きます is grammatically fine, but it sounds more repetitive and less natural in everyday Japanese. Once the topic is clear, it’s usually dropped.

What exactly does 好きな歌手 mean? Why is it 好きな and not something like 好きの歌手?

好き is a na-adjective (好きな + noun) when it directly modifies a noun.

好きだ / 好きです = “to like; to be fond of”
好きな + noun = “noun that I like”

So:

好きな歌手
= “(a) singer (that I) like” / “favorite singer”

You cannot say 好きの歌手.
When a na-adjective directly modifies a noun, it always takes な, not の:

好きな映画 = a movie I like
きれいな花 = a pretty flower
有名な人 = a famous person

What does の do in 好きな歌手のコンサート? Is it like “favorite-singer’s concert”?

Exactly. You can think of it as X’s Y or the Y of X.

好きな歌手 = singer (that I) like
コンサート = concert
好きな歌手のコンサート
= literally “concert of the singer (I) like”
= “my favorite singer’s concert / the concert of a singer I like”

So the whole chain is:

私の趣味は音楽で、
好きな歌手 の コンサート に …

“My hobby is music, and (I) go to concerts of singers I like …”

Why do we use に after コンサート: コンサートに行きます?

に marks the destination or goal with verbs of movement like 行く (go), 来る (come), 帰る (return).

学校に行きます。= I go to school.
日本に行きたいです。= I want to go to Japan.
友達の家に行きます。= I go to my friend’s house.

So:

コンサートに行きます。
= “(I) go to (a/the) concert.”

Here に is the natural particle for going to some event or place.

What does と mean in 友達と行きます?

Here と means “with”.

友達と行きます。
= “I go with (my) friend(s).”

This is a very common pattern:

彼女と行きます。= I’m going with my girlfriend.
先生と話します。= I talk with the teacher.
家族と旅行します。= I travel with my family.

Note: と has several uses (and, with, quoting), but in Xと行く it means with X.

Why don’t we need anything like 一緒に (together) after 友達と?

You can add 一緒に for emphasis, but it’s not required.

友達と行きます。
= I go with my friend(s). (Natural, already implies “together”.)
友達と一緒に行きます。
= I go together with my friend(s). (A bit more explicit.)

Both are correct. In many cases, 友達と行きます is enough; 一緒に just highlights the “togetherness” a bit more.

Where can ときどき go in the sentence? Why is it before 友達と here?

ときどき is an adverb meaning “sometimes”. Adverbs in Japanese are fairly flexible in position, especially near the verb.

Common placements:

ときどき友達と行きます。
友達とときどき行きます。
ときどき、友達と行きます。

All are understood as “I sometimes go with my friend(s).”
The version in your sentence:

…コンサートにときどき友達と行きます。

simply places ときどき right before 友達と, but it still modifies 行きます (“go”). Native speakers often put ときどき near the part they want to rhythmically emphasize, but grammatically it refers to the frequency of 行きます.

Could the word order be changed? For example, is this okay:
私の趣味は音楽で、ときどき友達と好きな歌手のコンサートに行きます。

Yes, that is fine and natural.

Japanese word order is relatively flexible as long as:

The verb comes at (or near) the end, and
The particles stay with their words.

So several variations work:

私の趣味は音楽で、好きな歌手のコンサートにときどき友達と行きます。
私の趣味は音楽で、ときどき友達と好きな歌手のコンサートに行きます。
私の趣味は音楽で、友達とときどき好きな歌手のコンサートに行きます。

All mean roughly the same thing. The differences are mostly subtle nuances in rhythm and slight emphasis, not in basic meaning.

Why is 友達 singular in Japanese but “friends” in English?

Japanese nouns generally don’t mark singular/plural unless you add something special (like たち, ら, etc.).

友達 can mean:
- a friend, one friend
- friends, some friends, my friends

The exact meaning is inferred from context.
In this sentence, 友達と行きます could be “with a friend” or “with friends”. In English, “with friends” sounds more natural, so that’s how it’s usually translated.

If you really want to emphasize plural, you can say:

友達たちと行きます。 (less common; sounds a bit childish or very specific)
何人かの友達と行きます。= I go with some friends.

But most of the time, simple 友達と行きます is enough, and the listener fills in the number from context.