On modern band and orchestral drums, the drumhead is placed over the opening of the drum, which in turn is held onto the shell by a "counterhoop" (or "rim"), which is then held by means of a number of tuning screws called "tension rods" that screw into lugs placed evenly around the circumference. The head's tension can be adjusted by loosening or tightening the rods. Many such drums have six to ten tension rods. The sound of a drum depends on many variables—including shape, shell size and thickness, shell materials, counterhoop material, drumhead material, drumhead tension, drum position, location, and striking velocity and angle.
Digital pianos typically use analog sensors for its keyboard action, as opposed to digital sensors of a regular keyboard and synthesizer. These sensors notably works in a similar way to those used in analog joysticks found on video game controllers, in which they the velocity input is converted from the key movement as well, not just the initial pressure of the key sensor.
Multi-scale fingerboard is an alternative design for guitars and bass guitars in which the lower-pitched strings gain more length and the higher-pitched strings get shorter, similar to the string lengths on a grand piano. The reason for the uneven scale length across strings is that it evens out the tension across all of the strings, it evens the timbre across the strings, and extending the lower string scales allows the string to produce harmonics that are more in tune with the fundamental.
Specific bass brands/models became identified with particular styles of music, such as the Rickenbacker 4001 series, which became identified with progressive rock bassists like Chris Squire of Yes, and Geddy Lee of Rush, while the StingRay was used by funk/disco players such Louis Johnson of the funk band The Brothers Johnson and Bernard Edwards of Chic. The 4001 stereo bass was introduced in the late 1960s; it can be heard on the Beatles' "I Am The Walrus." 
Before buying your first bass guitar, you need to make sure to consider each and every one of the factors above before settling on a specific model you want to buy. As you look at the various models, also make sure that the guitar feels comfortable to you personally as you test it out. Remember, you will be using this bass for a while, so you need to make that sure you are picking the best bass guitar in your budget for you.
No matter which digital piano you choose, you're in for something special. The instruments found on these pages all offer different features, so take a few minutes to think about your needs as a musician and go from there. Whether you go with a higher-end stage piano like the top-selling KAWAI MP11 Professional Piano or a student model Yamaha's NP12 61-Key Entry-Level Piaggero Ultra-Portable Digital Piano, any digital pianos here will enhance your musical journey.