In the world of pianos, size does indeed matter. Piano manufacturers design their products according to the needs of a particular venue or performer. A professional concert pianist playing with a full orchestra might need a full-sized concert grand piano, while an accompanist for a small church may only need an upright piano. There are other gradations along the way, and even some electronic elements to consider.

By far the largest type of piano produced is called a concert grand. Concert grand pianos can often be found in recital halls and orchestral stages. Because of their size and tuning requirements, it is not unusual for master pianists to come to the pianos, not the pianos to the pianists. Concert grand pianos generate very vibrant tones, especially in the lower registers. This is important when a solo pianist must compete with a full orchestra.

For most people, the largest practical pianos are either grands or baby grands. These pianos use the same horizontal soundboard configuration as a concert grand, but are not nearly as long. A typical grand piano is about 3/4 the size of a concert grand, and a baby grand is about 1/2 the size. Both pianos use a hinged lid to direct the sound towards the audience during performance. Many schools of music keep several grand and baby grand pianos available for student recitals or for visiting performers.

Since space is always at a premium in most homes, many amateur pianists select upright pianos for private use and rehearsals. Upright pianos use vertically mounted strings to significantly reduce horizontal length. This means that upright pianos can be installed in living rooms or dens without taking up any more room than a couch or bookcase. The sound of upright pianos may not be as full as grands, but it is perfectly suitable for informal performances. Many upright pianos are handed down from generation to generation.

With the advent of modern electronics, some pianos can be equipped with pick-ups and amplifiers to create an entirely new sound. Electric pianos first became popular with jazz musicians, because the pianist could duplicate the solo breaks of a guitarist along with the chording of a piano. Because electric pianos can be carried on the road without the detuning problems of traditional pianos, many travelling bands use electric pianos and synthesizers almost exclusively.

Some piano students may encounter rehearsal pianos with a limited number of octaves. These pianos are mostly intended to accompany music theory classes or for basic keyboard courses. Some recent do-it-yourself piano courses even include a very small electronic keyboard which can be rolled up and stored between sessions.