Is the word maestro the same in Brazilian and European Portuguese?

Yes

The spelling, meaning, and grammar of the word "maestro" are identical in both Brazilian and Continental Portuguese. The only difference lies in pronunciation.

In Brazilian Portuguese, vowels tend to be more "open" and clearly articulated. When pronouncing "maestro," a Brazilian speaker will likely pronounce the "e" with a clear, distinct sound. In Continental Portuguese, vowels—especially unstressed ones—undergo "vowel reduction," meaning the "e" may sound much more closed, muffled, or even almost silent, depending on the regional accent.

Brazilian Portuguese Examples

1. O maestro está regendo a orquestra. (The conductor is conducting the orchestra.)
2. O maestro está ensaiando a peça nova. (The conductor is rehearsing the new piece.)
3. O maestro está pedindo silêncio no teatro. (The conductor is asking for silence in the theater.)
4. O maestro está preparando o concerto de hoje. (The conductor is preparing today's concert.)
5. O maestro está conversando com os violinistas. (The conductor is talking to the violinists.)

Continental Portuguese Examples

1. O maestro está a reger a orquestra. (The conductor is conducting the orchestra.)
2. O maestro está a ensaiar a peça nova. (The conductor is rehearsing the new piece.)
3. O maestro está a pedir silêncio no teatro. (The conductor is asking for silence in the theater.)
4. O maestro está a preparar o concerto de hoje. (The conductor is preparing today's concert.)
5. O maestro está a conversar com os violinistas. (The conductor is talking to the violinists.)