Every month I post a new, and absolutely free, music game at www.playwithsound.com where clicking on 'this month's free game' will take you right to it.
June's free music game is called Echo Me and is highly adaptable. It can be played with voices or instruments, can be made harder or easier and can be played educationally, but enjoyably, with children from five to one hundred and five. So versatile is this game that it can be played in a few odd moments as a filler or can be stretched for as long as your group has an appetite for it. And this can be a long time if you build it up in steps, as suggested, and add instruments to the mix. Have a go and let me know what you think.