I remember when my daughter Ebony had her classical piano music lessons her teacher, Yelena Kurinets [a great classical music piano teacher], when introducing a new piece, would first play part or the entire piece to my daughter. The first thing she would ask Ebony was to give a description of the piece, i.e., the mood of the piece. She would ask my daughter to state if the piece was happy, playful, fun, exciting, sad, dramatic, scary, or some other descriptive word. She wanted her to learn the mood of the piece in order to know how to play the piece. What later became obvious was that pieces had a certain flavor according to the key of the piece. Pieces that were in a major key, like C-Major, E-Major, etc. were almost always bright happy pieces. Pieces that were in a minor key, like D-minor, E flat-minor, etc., were almost always more dramatic and sometimes darker pieces than those with a major key.

The great composers of classical music would put a piece in a certain key to portray the mood they wanted. So, for the most part, if they would want the piece to give a bright, happy feeling to it, they would use a Major key. If they wanted a piece to portray a darker and or dramatic mood, they would use a minor key. [as always in classical music, there are exceptions]
I will give you examples from three of my favorite composers, Wolfgang Amadeus Mozart, Felix Mendelssohn, and Antonin Dvorak, to show how the key of the piece of music helps determine the mood of the piece.
The quintessential classical composer W. A. Mozart, composed 27 piano concertos, most of them truly great piano concertos. You will hear how the Mozart piano concerto #25 in the key of C Major displays a bright happy character, while Mozart’s Piano Concerto # 24 in C minor portrays a more serious and dramatic mood.
All of Felix Mendelssohn’s pieces have a very melodic beautiful characteristic, but they all don’t have the same mood. Mendelssohn’s Symphony #4 in A Major [Italian Symphony] has a playful, bright happy mood, while his Symphony #3 in A minor [Scottish] has a more dramatic, thoughtful, serious mood.
The great Romantic composer from the Czech Republic, Antonin Dvorak, was known for his stirring pieces and beautiful melodic music. He composed 9 great symphonies and I have chosen the final movements of Symphony #8 [in a Major key] and #9 [in a minor key] to show you how the key of the piece can help determine the different mood of the piece. The final movement of Dvorak’s Symphony #8 in G Major has a very positive and triumphant mood. While in movement 4 of Dvorak’s exciting Symphony #9 in E minor [From the New World] there is a dramatic, tense [and in some places-pensive] feeling/mood.
As I say always, please turn up the volume and enjoy this great music from Mozart, Mendelssohn and Dvorak with two of their pieces: One in a Major key and one in a minor key, and hear how the key is the key to the mood.
W. A. Mozart: Piano Concerto #25 in C Major, Movement 3 Allegretto:
W. A. Mozart: Piano Concerto #24 in C minor, Movement 1, Allegro:
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Felix Mendelssohn: Symphony #4 in A Major [Italian], movement 1, Allegro Vivace:
Felix Mendelssohn: Symphony #3 in A minor [Scottish], Movement 1, Andante con moto – Allegro:
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Antonin Dvorak: Symphony #8 in G Major, Movement 4, Allegro ma non troppo:
Antonin Dvorak: Symphony #9 in in E minor [From the New World], Movement 4, Allegro con Fuoco: