HAMAMATSU, Shizuoka Pref. — Makers of musical instruments are pouring their energy into developing hybrid pianos that combine traditional craft-making skills with digital technology.

Yamaha Corp.'s latest product is the AvantGrand, which is touted to have the sound of a grand piano without the girth. Kawai Musical Instruments Mfg. Co. has developed a piano with a soundboard speaker, while Roland Corp. began marketing the electronic V-Piano last year.

Competition for developing and marketing hybrid and electronic pianos is expected to intensify as sales of acoustic pianos slide.