Excellent trip! It is a rather long day especially if you include Russet Lake as we did, but well worth the effort. The trail is well-graded up to Singing Pass and we were able to keep a fast pace all the way there. Only when you get to within forty minutes of the pass do the views really open out from the trees, but from that point on the trail is spectacular. Owing to our ridiculous snow year, the meadows are in full bloom right now and they are everywhere. This was the greatest volume of subalpine flowers I've ever seen. The views are big, big, big! Most of the mountains you see are across valleys so there isn't much in-your-face mountain action unless you continue to Russet Lake, but what you see is expansive. Outside of an airplane it would be hard to find a better large-scale view of the mountains of the Garibaldi Park region. We even saw as far as the Tantalus Range down near Squamish!
Heading back over the Musical Bumps to the gondola was more flower-filled meadows and huge views. The bumps are a little steeper than I expected and there is more elevation to gain, and lose, and gain again than I had hoped, but that's what I get for not researching a trip in advance. We kind of lost our way for a bit past Flute Summit and didn't manage to find the High Note trail, but the route we ended up taking was probably faster and we didn't have much time to spare to catch the gondola. The trail does split a few times in the region between Flute and Piccolo Summits and it appears as though some of the trail posts have been knocked over or are missing. Check the gondola schedule, it would SUCK to have to walk down to the parking lot from up there. Nobody checked us for a ticket as we had heard, so the fifteen-minute ride down was free.
In terms of water, there is a lot while you are heading up to Singing Pass and Russet Lake and very little up on way back over the Musical Bumps, which are completely exposed to the sun.
Making a side trip to Russet Lake from Singing Pass is recommended. Give yourself an extra two hours for a there-and-back unless you want to just immediately turn around once you hit the lake - and that would be silly.