Bit 0 = 1: This selects ADC channel 0, not ADC channel 1.
That is not correct. MUX3...0, the lower 4 bits of ADMUX, select ADC channel 0-8, where values of 0 = channel 0, 1 = channel 1, 7 = channel 7, 8 = temperature sensor and >8 are reserved.
Here is how the OpenMusicLabs fht_adc.pde example initializes the ADC:
ADCSRA = 0xe5; // set the adc to free running mode
ADMUX = 0x40; // use adc0
DIDR0 = 0x01; // turn off the digital input for adc0
The "4" in the upper nibble selects AREF to be AVCC and ADLAR = 0 (data are right adjusted).
To choose channel 1, set ADMUX = 0x41;
As the author of the OpenMusicLabs pages discusses, it is a good idea to turn off the digital inputs associated with each channel, to reduce noise.