‘Dan Zanes Song Gusto Hour’ and ‘PhilharMonster!’

It’s going to be a musical Halloween weekend at Symphony Space. On Saturday at 11 a.m., young fans are invited to what may be the only concert activity that’s more fun than listening to Dan Zanes: singing with him. At “Dan Zanes Song Gusto Hour,” this beloved family rocker and folk artist will encourage audience members to join in just as loudly as they wish as he performs his hits, which will include selections from his latest album, the aptly titled “Get Loose and Get Together!” (Festival Five Records). On Sunday at 4 p.m., it’s time for some haunting — in all senses — symphonic pieces, as young musicians from the InterSchool Orchestras of New York offer “PhilharMonster!” Dressed in costume — they encourage the audience to do the same — the players will perform sepulchral works from classic movies and the classical canon, including Grieg’s “In the Hall of the Mountain King” and Berlioz’s “March to the Scaffold.”