Mi primo toca el bajo en una banda de rock local.

Spanish uses different verbs for “to play”:

• tocar = to play an instrument (or to touch)
  • Mi primo toca el bajo. = My cousin plays the bass.
• jugar = to play a game or sport
  • Mi primo juega al fútbol. = My cousin plays soccer.

So with musical instruments, always use tocar, never jugar.

Toca is the third person singular, present tense of tocar:

• Infinitive: tocar (to play [an instrument])
• Yo toco – I play
• Tú tocas – You play (informal)
• Él/Ella/Usted toca – He/She/You (formal) plays
• Nosotros tocamos – We play
• Ellos/Ellas/Ustedes tocan – They/You all play

Since mi primo (my cousin) is like él (he), you use toca.

In Spanish, musical instruments usually take the definite article:

• Tocar la guitarra – to play the guitar
• Tocar el piano – to play the piano
• Tocar el bajo – to play the bass

So you normally say tocar + article + instrument, even if in English you don’t use “the.”
You would not usually say mi primo toca bajo in standard Spanish.

Bajo can mean different things depending on context:

• Adjective: bajo = short, low
  • Un hombre bajo – a short man
• Noun: el bajo = the bass (instrument or musical register)
  • Tocar el bajo – to play the bass (guitar)

In toca el bajo, it’s clearly the noun “bass,” because:

• it follows tocar, which is used for instruments, and
• it has the article el.

So here it definitely means the bass (guitar), not “short.”

In Latin American Spanish, el bajo in this context almost always means the bass guitar in a band. People may specify if needed:

• bajo eléctrico – electric bass
• bajo acústico – acoustic bass
• contrabajo – double bass (upright bass)

But in a rock band context, toca el bajo is understood as plays bass guitar.

For family members, Spanish usually uses possessive adjectives (mi, tu, su, nuestro, etc.) directly before the noun:

• mi primo – my cousin
• mi hermano – my brother
• mi mamá – my mom

You can say el primo mío, but that sounds more emphatic or specific (“that cousin of mine”) and is less common in a simple sentence like this.
The normal, neutral way is mi primo.

Yes:

• primo = male cousin
• prima = female cousin

So:

• Mi primo toca el bajo… – My (male) cousin plays bass…
• Mi prima toca el bajo… – My (female) cousin plays bass…

The possessive mi doesn’t change for gender; only primo/prima changes.

With singular family members, Spanish normally does not use the definite article when you use a possessive:

• mi primo – my cousin (not el mi primo)
• tu hermana – your sister (not la tu hermana)
• su padre – his/her/their father

So the pattern is: [possessive] + [family member, singular] with no article.

Spanish uses en (in) for membership in a group or band:

• Toca en una banda. – He/She plays in a band.
• Canta en un coro. – He/She sings in a choir.

Using a here would be incorrect (toca a una banda is wrong). The natural preposition is en.

Both can mean “band,” but there are nuances:

• banda:
  • In Latin America, commonly used for rock/pop bands, but also brass bands or marching bands depending on context.
  • Also names specific genres: banda music in Mexico.
• grupo (musical):
  • Very general: any music group, pop group, rock group, etc.
  • Often heard as grupo de rock, grupo musical.

In una banda de rock, nobody is confused; it’s clearly a rock band.

Both are possible, but they sound a bit different:

• una banda de rock local

  • Literally: “a band of local rock,” but understood as “a local rock band.”
  • Emphasis slightly more on the music being local rock.

• una banda local de rock

  • More like “a local band of rock.”
  • Emphasis a bit more on the band being local.

In everyday speech, una banda de rock local is very natural and common. Word order with adjectives can slightly shift nuance, but both are grammatical.

Rock is a loanword from English. In Spanish:

• It’s usually written the same: rock.
• Pronunciation is adapted slightly to Spanish sounds, more like [rok] with a tapped/flapped r.
• It does not normally change for gender or number:
  • música rock – rock music
  • bandas de rock – rock bands

So banda de rock is the standard way to say “rock band.”

Yes, context can allow that reading.

• Mi primo toca el bajo… literally = My cousin plays bass… (habitually).
• If you want to be very clear that it’s happening right now, you’d usually say:
  • Mi primo está tocando el bajo en una banda de rock local.

But Spanish present simple (toca) can sometimes cover what English expresses as present continuous (is playing), especially if the context suggests a current ongoing situation (like talking about what he’s doing these days).

You need to pluralize both the subject and the verb:

• Mis primos tocan el bajo en una banda de rock local.

Changes:

• mi primo → mis primos (my cousin → my cousins)
• toca → tocan (he/she plays → they play)

El bajo stays singular, because they might be sharing the role, or you’re just talking about the instrument in general. If you specifically meant they each play their own basses, you could say los bajos, but that’s less common in this type of sentence.