Band Hero Instruments on Lego Rock Band (Wii): Not Compatible

No. The instrument protocols are incompatible:

• Band Hero (Wii): Uses standard Bluetooth.
• Lego Rock Band (Wii): Uses a proprietary USB dongle (2.4 GHz RF).

The game software only recognizes its own licensed dongle/instrument pair. Even if physically connected, the signals won't match.

You must use the Lego Rock Band instruments (or standard Rock Band 1/2/3 Wii instruments with their dongles).