MUSIC: KCRW, Americano at Hotel Vitale, and Om Records present Soundcheck, a free outdoor show featuring a stripped down set by Brooklyn's Si*Se, who have a Latin, downtempo, and soul vibe. Space is limited, so get there early, and be sure to RSVP for free entry.

5 to 8 p.m. // Americano Restaurant & Bar (8 Mission St) // $10 (free with RSVP)

LITERARY: Meridian Music begins their Fall 2010 series with Call And Response, in which poet Dottie Grossman will read her poems aloud and then improvising trombonist Michael Vlatkovich will respond. Neither knows in advance what the other will choose to do, creating an "appealing artistic tension in a unique way" and each medium will enhance the other without overpowering it.

7:30 to 9 p.m. // Meridian Gallery (535 Powell St) // $5-10

SCIENCE: At How to Make a Telescope, local amateur astronomer Douglas Smith, whose 16.5" primary mirror Dobsonian truss-tube telescope, FirstLight, was exhibited at this year’s Maker Faire, will explain basic optics, discuss the different types of telescopes and their components, and demonstrate the process of making those components.

7 p.m. // Bazaar Cafe (5927 California St) // free (purchase of food/beverage is appreciated)