What is the meaning of 'Crescendo, cresc.'?

The term 'crescendo' or its abbreviation 'cresc.' refers to a gradual increase in loudness or intensity of music during a passage. This instruction is commonly used in musical notation to guide musicians on how to produce a swelling effect in the volume, enhancing the emotional impact of the piece. Crescendo helps build tension and excitement, allowing the music to flow dynamically and engage listeners more effectively.

In the context of the other options, playing softer refers to decrescendo, which indicates a decrease in volume. Playing with emotion can certainly enhance a performance but does not specifically pertain to the volume dynamics of the music. Lastly, playing at a slower tempo relates to the pace of the music rather than its loudness. Thus, the correct understanding of 'crescendo, cresc.' is about the gradual increase in sound, making it the appropriate choice.