minimum scale rate set out by the union. Heavily in-demand session musicians may earn much more. The union rates may vary based on whether it is a music recording versus film/television recording. While the film/television rates may be lower, there may also be residual payments to compensate them for reruns, DVD sales, streaming usage, and so on. Session musicians often have to bring their own instruments, such as in the case of guitar, bass, woodwinds, and brass. It is expected that studio musicians will have professional-tier instruments that are well-maintained. In some cases, larger or heavier instruments may be provided by the recording studio, such as a grand piano or Hammond organ and Leslie speaker. In certain cases, a session musicians may bring some instruments or musical gear and use them with larger instruments that are provided by the studio, such as a synthesizer player, who might bring rack-mounted synth modules and connect them to the studio's MIDI controller stage piano. Similarly, if the studio has a selection of well-known bass amplifiers and speaker cabinets, a bass player may only have to bring basses and effect units. The requirement to read different types of music notation, improvise and/or "play by ear" varies according to the type of recording session and the genres of music being performed. Classical musicians and many jazz and popular music musicians are expected to read music notation and do sight-reading. In jazz, rock, and many popular music genres, performers may be expected to read chord charts and improvise accompaniment and solos. In country music, performers may be expected to read Nashville Number System charts and improvise accompaniment and solos. In many traditional and folk music styles, performers are expected to be able to play by ear. Session musicians need a nuanced sense of the playing styles and idioms used in different genres. For example, a sax player who mainly plays jazz needs to know the R&B style if they are asked to improvise a solo in an R&B song. Similarly, a bass player asked to improvise a walking bassline in a rockabilly song needs to know the stock lines and cliches used in this genre. Regardless of the styles of music session musicians play, some qualities are universal: punctuality in arriving at the session; rhythmic and intonation precision; ability to play with good ensemble and excellent blending with the other performers; willingness to take direction from